How Fresh Is Your Fresh Water?

According to the ancient Greek poet Pindar, "Water is the best of all things." But would Pindar, who lived 518-438 BC, even understand our contemporary RVing concept of carrying fresh water with us, or of tapping into a different source of city water each evening? Certainly there was a high degree of importance placed on the availability and the freshness of water during those ancient times, not to mention the importance of learning the refined art of dry camping; talk about real boon-docking! And so it should be today. RVers should wonder just how fresh, (read - safe), is the water at the various campgrounds we visit.

The Bad,

Not long ago, USA Today analyzed millions of records from the nation's 170,000 regulated water systems during the years 1993-1997 and concluded, "Each day, millions of Americans turn on their taps and get water that exceeds legal limits for dangerous contaminants. Millions more get water that isn't treated or tested properly, so there's no telling if it's clean." Think water worries are just a dilemma from the long ago past? The worst outbreak of a waterborne illness in U.S. history was just a few short years ago in 1993 when a parasite in Milwaukee's water system killed 111 people and made 403,000 people sick. A report by the Medical College of Wisconsin and the EPA estimates that 7.1 million Americans suffer nausea or diarrhea yearly just from foul water. The bottom line? Take a proactive attitude and be sure the water you allow into the fresh water system in your RV is indeed fresh and free from contaminants

The Ugly,

We've all experienced bacteria-causing, foul tasting and smelly water at some time during our RV excursions, but are there more serious dangers lurking below the surface? (pun intended). Just what pitfalls are we to be aware of? Microbiological water enigmas center around five categories; viruses, molds, algae, parasites and bacteria. Specifically, waterborne bacteria and some hearty parasitic protozoa are a serious concern everywhere since the majority of these are often not affected by typical disinfection processes. In fact no U.S. municipal or regional waterworks can guarantee killing or removing all of them. Add this to the fact that the most dangerous of the parasitic cysts, Cryptosporidium, is found in virtually every surface water supply worldwide. Small wonder there should be caution.

The very name itself should induce an awareness; "crypto" means hidden or secret and the word "spore" means seed or germ. Cryptosporidium is literally a "hidden germ". A leathery shelled parasite, it is just 3-7 microns in diameter; (a human hair measures 100 microns). Cryptosporidium causes severe, flu-like symptoms and must simply be left to run its course since there is no cure. Once ingested and broken down, four additional protozoa emerge from each cyst and begin to reproduce. As widespread as Cryptosporidium has become, the EPA still does not require municipal water systems to test for it. Yet another good reason to take an assertive stance regarding the water you drink and cook with.

And The Good There are ways, however, to combat and protect against harmful bacteria and parasites like Cryptosporidium and Giardia. Effectively, there are three things RVers can do;

One, boil all the water used in the fresh water system - Boiling is a good way to kill bacteria, viruses and parasites though this is not very practical.

Two, use bottled water - Again, not very practical for RVers. It can also be expensive, inconvenient and still no guarantee that it's pure. Some published reports even suggest that 25% of all bottled water contains known carcinogens and about 20% contain industrial chemicals. Wonderful.

Three, use a point-of-use, (POU), water filtration system. This option is the most viable, the most convenient and the most readily available to all of us. Many fine companies have jumped to the fore with an assortment of effective filtration products.

Filtration systems can run the gamut from simple mechanical strainers to the more exotic reverse osmosis and superchlorination systems. The best system for you depends on your traveling habits and the cleanliness of the water you are likely to run into.

Many POU systems are installed under the galley sink and deliver fresh water directly to a dedicated faucet for cooking and drinking. However, many RVers prefer the very popular, in-line external units that allow finite filtration without losing that precious under-the-counter storage space. The added plus is that all the incoming city water is processed, so you can enjoy RV showers without the heavy metals and odors sometimes found in park systems. As an additional precaution, use an in-line filter as you fill the fresh water tank on the RV. As water is processed through the filter just before it enters the city water inlet or the inlet to the fresh water tank, sub-micron particles, bacteria, cysts and unwanted chemicals are removed by the active filtering media, usually carbon.

So just how does activated carbon remove the impurities? By the process of adsorption. No, that's not a typo. Adsorption is the physical process that occurs when dissolved molecules, bacteria and other particles are attracted to and attach themselves to the surface of the adsorbent, the carbon. Kind of like a magnet sticking to a metal surface. Quite different from the more familiar process of AB-sorption, which can be likened to a paper towel soaking up water.

As an adsorbent, especially when filtering trihalomethanes, (THMs), volatile organic contaminates, (VOCs), pesticides and fungicides, activated carbon is quite effective because it's surface area is enormous; about 1,000 square meters per gram. To put that into perspective, a piece of carbon the size of a single pea will yield a surface area a little over the size of half a football field! But as with many good things, there is a downside to using carbon as the sole filtering media. Exposure to chlorine in water supplies will quickly deteriorate the adsorbing qualities of carbon, rendering it minimized or useless in as little as 200 gallons, so if you use a chlorine product to de-winterize your RV water system, be sure to remove or bypass the filter first!

As an alternative, companies such as Hydro Life and General Ecology, have improved upon the process of carbon-only filtration. General Ecology has developed a unique technology employing a "Structured Matrix^™" filtration component which instantly filters the water without the use of chemicals, double treating or delay time.

Hydro Life has perfected a filtering media which employs carbon along with their patented media called KDF. KDF causes an electro-chemical reaction which neutralizes harmful chemicals and dangerous metals such as lead. As an example, chlorine is broken down into a harmless chloride after being zapped with the .04-volts produced when the water passes through the KDF. The water then passes through the carbon to complete the filtering process.

An established maker of exterior and interior POU systems, Hydro Life also has developed a unique bracket to hold most external filters. A mounting plate is secured to the sidewall of the RV and a second plate is provided for stowing the filter inside a compartment. The nice feature about this holder is that it can be reversed to hold either the canister-type filter or the in-line version.

Other suppliers with a high degree of brand recognition include Everpure^® and Culligan^®. The popular Everpure system utilizes a superchlorination/dechlorination process to attack bacteria, viruses, cysts, rust and other heavy metals. All of which can lead to foul smelling water.

Another name synonymous with RVing is SHURflo^®. Aside from their very popular water pump, SHURflo also offers the Waterguard Water Filter Kit. This cartridge-type filter can be mounted inside, under the counter, or used as an in-line, exterior filter. One Waterguard model incorporates a handy bypass valve for easy cartridge replacement or for winterizing purposes. Like the Culligan canister-type filter, the Waterguard replacement cartridges are available with an assortment of filtration media depending on the degree of filtration needed.

Look for a filtration system that satisfies the requirements of Standard 53: Drinking Water Treatment Units - Health Effects, as determined by NSF, a third party certifying agency. Though no official standard exists for POU filters, virtually all public health officials adopt the standards of the NSF.

To ensure proper filtration efficiency, always replace the filter media or cartridge as least once a year. Keep in mind, the longer a filter is in service, the less effective it becomes. At some point, an exhausted filter media will begin dumping contaminates back into the system. In severe cases or when tainted water has been encountered, it may be necessary to replace the filters more often.

Perhaps what Pindar really wanted to say is, "Fresh and clean RV water is really the best of all things!" Well, we, at least, can enjoy that sentiment today. Be sure to check out the filtration devices on your next visit to your local Camping World store.

Do It Yourself, or Take It to a Pro?

By Gary Bunzer

Recreational vehicle service and maintenance - we have all had exposure to its necessity at one time or another. In the vast realm of RV options such as type of RV, floor plans, color schemes, types of chassis', interior furnishings and other assorted appointments, just to name a few, there can be no denying the "non-optional" eventuality of service, maintenance and repairs required by many of the components on our coaches. This is especially evident as we keep and utilize the motorhome over longer periods of time. Virtually all coach manufacturers agree that in order to receive the most out of the recreational investment you've made, adequate maintenance must be performed on certain components on every RV. In fact, a typical motorhome with a generator and two roof air conditioners has a minimum of sixteen retail hours (or more), of mandated maintenance that needs to be performed each and every year! That's right, sixteen hours worth. And many coaches mandate up to 20 or more hours of annual service. At an average retail labor rate of, say $95.00 per hour, that could total almost $1,900 per year for just trying to avoid a major problem.

Product manufacturers oftentimes will indicate the necessity for periodic maintenance on their individual products each season as a precautionary step in obtaining the optimum use of that product. It is noted, however, that all products will not automatically self-destruct if these sixteen hours of maintenance are not performed, but it is highly recommended and one would certainly gain additional life from these products if they were to be maintained and checked periodically.

Some of those areas that may need seasonal attention and that you may want to consider doing yourself are not limited to, but do include:

• checking and sealing the roof, windows, storage compartments and doors

• cleaning the propane gas appliances

• changing the oil in the generator and chassis engine and checking all fluid levels

• cleaning the filters in the roof air conditioners

• cleaning and treating your holding tanks

• flushing and sanitizing your fresh water system

• performing battery maintenance

• winterizing and de-winterizing the coach

• installing add-on accessories

There are basically two types of RV service; crisis repairs and preventive maintenance. The aforementioned sixteen hours would be classified as time devoted to preventive maintenance - those steps usually performed before there is an actual need for repair. Kind of like preventive medicine. Something you do now to prevent something worse from happening later. A little insurance, if you will. Crisis repairs, on the other hand, offer no options. The problem is already at hand and readily in the now! A few examples of crisis repairs would be an abnormally worn tire, a blocked cooling unit on the refrigerator, a blown engine, a burned out roof top air conditioner compressor.
That said, here's the important thing to remember; preventive maintenance will minimize the frequency and the degree of crisis-type repairs. Routine tire inspection and careful study of inflation pressures, checking and cleaning the refrigerator components and checking the propane gas pressure, regular oil changes, and periodic cleaning of the air conditioner filters can all prevent the above crisis repairs from happening. Realize it is a choice each RVer must face - Preventive maintenance, or crisis repairs. There is no third option.

Do It Yourself?
Alas, this discussion is not really about the types of RV service, but about whether or not you should even attempt some of the maintenance items yourself. Can we as owners control our own RV repair destiny? Is that possible or feasible, or should we simply leave all types of service up to the professionals? I, for one, have always been in favor of owner involvement in the technical arena concerning RVs - to a certain extent. I've devoted a large junk of my time over the last forty years educating the RV owner specifically in some of these areas. But you did notice I had a quasi-disclaimer tacked onto the end of that earlier sentence. Unless properly trained and prepared, I do believe RV owners should simply not attempt to make repairs or perform service on any RV, product or component.

This is especially true during any factory warranty period of a new coach. All repairs should be performed by authorized persons only during this time. In some cases, warranties may even be voided or manufacturer liability lessened if unauthorized repairs are performed (In the context of this article it is assumed your coach is not under a warranty situation). But most maintenance items, though mandated by the product manufacturer or coach builder, are not covered by new or extended warranties. Some items are simply destined to be the sole responsibility of the RV owner. Rarely, if ever, are maintenance items ever covered under warranty. In such cases, and in instances of out-of-warranty RVs, certain owners will actually enjoy delving into the various technical aspects of their coaches. The key is knowing when to actively participate and when to simply make an appointment at your local service facility.

So just who among us should even consider performing maintenance tasks and minor servicing on our rigs? Here's some demographics. An informal survey taken at one of my recent owner maintenance seminars revealed that the motorhome owner who actively performs routine service typically:

• is mechanically inclined, or has past experiences in the blue-collar trades.

• has an impressive assortment of hand tools and testers.

• has a keen interest in the technology of the motorhome.

• travels and camps in remote areas, far from regular RV service centers and has no choice but to learn to become an RV service tech.

• has as much or more of a technical aptitude than the non-certified professional.

• is now, or has been a full-time RVer.

If you recognize yourself in these listed characteristics or are wondering whether or not you should even attempt a maintenance task, here's a few considerations for you to ponder. Keep in mind, however, this list is not all-inclusive and all items may not apply evenly across the board. These are just a few thoughts to explore.

Review your own mechanical/technical aptitude - The important thing here is to realize your limitations. As you ponder a task, ask yourself, "Can I physically perform the steps necessary to do this?" Many items in, under, on and around motorhomes require physical dexterity. Physical limitations may prohibit some of us from performing certain maintenance items. Sort of like when the brain says "yes," but the ole 'bod says "no way!" Also, realize and admit it when the subject at hand is truly over your head. There is no need to be a hero. You definitely do not want to risk converting a simple maintenance task into a costly crisis repair! Cha-ching! It will cost substantially more to undo an error than to simply make an appointment with a service center if the subject is beyond your scope. You aren't expected to know absolutely everything about your RV, but you should be able to honestly recognize the point at which you do not understand something. This maxim is true even with professional service technicians as well. Foolish is the RVer who trusts his coach to a service shop that proclaims its technicians know all there is to know about recreational vehicles.  

Have a willingness to learn - If you truly want to be able to perform some routine maintenance items, be willing to do a little homework. Servicing LP related appliances and components, for instance, virtually mandates a basic understanding of the sequence of operation of that appliance. Both electrically and with the flow of the propane gas. Each appliance is different, but your advantage is that you only need to learn those that pertain to your RV. And it's not that difficult to learn. Oh, it requires reading and studying the literature that came with your coach, but for the most part, it can be enjoyable. Especially when you consider that any knowledge gained and then applied may ultimately save real dollars in repair costs.

In cases where the owner's manual or user's guide has long ago disappeared, contact the component manufacturer directly. Most would be more than willing to make available the literature you need. You wouldn't think of jumping in a motorhome and taking off down a road you've never been on before without a road map or at least a general knowledge of where it leads. So it is with most technical matters on your coach.

Be properly equipped - Be aware that many maintenance tasks require a selection of tools and that some require specialty tools that you may not have in your tool kit. An example of such a tool would be the long flue brush needed for cleaning and servicing the RV refrigerator. If you commit to performing this step yourself, purchasing the needed specialty tool would be a wise investment. Aside from the flue brush, here are a few more specialty tools you may want to eventually acquire:

• Propane manometer.

• Battery hydrometer - one that is temperature compensated is more accurate.

• Volt, Ohm, multi-meter (VOM) - a digital one is best, but any is better than just a simple test lamp. 

(A detailed list of RV specialty tools will be featured in my, soon-to-be-released eBook, so stay tuned for that!)

Obtain replacement parts - Pay close attention also, if replacement parts are required. As an example, when performing a cleaning on the RV furnace, it is required that certain gaskets be replaced. Be sure to have those gaskets on hand prior to beginning the cleaning. One goal should be to keep the down time to a minimum. Always keep a small assortment of frequently replaced parts on hand.

Gather all the necessary tools and parts before starting your maintenance task. If you are performing maintenance on any electrical item, if available, always have a wiring diagram or schematic available as part of your resources. Most diagrams are usually included in the owner's literature and many will come with the replacement parts.

Consider the time factor - Always plan your approach to any maintenance task appropriately. Realize that all maintenance requires time. Be sure to allot yourself plenty of time to complete whatever it is you are undertaking. Do not rush yourself. You are more likely to omit a step or make a mistake if you are under pressure to complete a task when in a hurry. Remember, the next time you perform that same task, the time element will be reduced. Familiarity and repetition will breed speed.

How to "Do It Yourself"
Okay, so you feel like you just may qualify as a true RV "do-it-yourselfer," so now what? Well, now for some strategic planning and implementation. The following suggestions will get you started.

Prepare a proper and clean work area - Having a clean work area for whatever the task may be is vital in order to avoid confusion and also help keep the coach clean if you must traipse in and out of it several times. When servicing the appliances for example, it is best to perform the maintenance tasks with the appliances left in the installed positions. An exception would be the RV furnace. In some instances concerning the furnace, better results are attained if the furnace is removed and the work performed on a bench.

Also, in some cases, the absorption refrigerator may need to be partially removed to gain access for cleaning. Therefore, be sure to cover and protect carpeting or finished floors. When changing the oil in the generator or on the chassis engine, have an area cleared so complete access is easily accomplished. Don't forget to have your replacement oil ready to go before you remove the drain plug!

If you will be needing electricity, have your extension cord uncoiled and strategically placed prior to starting. Likewise, if using a drill motor, have the correct size drill bit, or screwdriver tip at hand. Proper preparation will make any maintenance task easier. Did you remember to allow enough time to do the work?

Have all replacement parts ready to go - Have all replacement parts prepared and laid out for easy access. If your maintenance task involves threaded fittings, a handy tip is to apply the correct sealant or Teflon tape before actually starting the work. It's much neater and easier when your hands are relatively clean. Lay the fittings aside and cover them with a shop towel or cloth until needed. If the new parts need any type of pre-assembly, do it now, before you get engrossed in the task at hand. If some parts in a repair kit will not be needed, separate and discard them prior to beginning. This will simplify your repair and avoid any confusion you may encounter later when you realize you have a few parts left over.

Obtain the necessary support materials - As mentioned earlier, have all wiring diagrams, service notes, installation instructions or any other type of resource open and within easy reach before starting the job. If you feel you may need additional help or support information, postpone the maintenance until all the necessary information is in your hand. Remember, preparation is much easier for a preventive maintenance procedure as opposed to an unwanted crisis repair. Also, keep in mind most maintenance tasks are available on the RV Doctor's Do-It-Yourself DVD. Additionally,  local community colleges may offer classes for the RVer and RV shows offer seminars on RV maintenance.

Backup vehicle - It's always advisable to have another available vehicle, "just in case." Whether it's a neighbor's truck, or a second vehicle of your own, perhaps it's the small car you usually tow behind your rig, in any event, always plan to have a mode of transportation available just in case you forgot something or for emergencies.

Establish a relationship with a local service facility - This step is vital. Even though you may want to perform some maintenance yourself, always get to know a local dealer or service center in your area. Aside from being there to order parts for you, they can also be a good source of information. They should work in concert with you and not feel threatened that you elect to perform some of your own maintenance tasks. Obviously, you will need to rely on them for any technical area you decide not to pursue, and there will be plenty left for them to do.

All major repairs and many items that require specialty equipment is best left to the professional shop as discussed. Of course, you will want to check out your local area to find the appropriate service department that best fits your needs. All service facilities are not created equal. Be sure your shop is staffed by qualified, Certified RV service technicians!

Additional tips - Never attempt to adjust the RV generator yourself. This is one area that is definitely better left to your service shop. Many specialty tools are required, as the generator needs to be load tested while making governor and carburetor adjustments. Load banks and specialty testers are beyond the scope of the do-it-yourselfer. Just remember that on the RV generator every mechanical adjustment that is made has an electrical result. You cannot tune a generator by ear. This item is for the professional.

Also, as briefly mentioned, never attempt to adjust the propane regulator. This too, is a job for the pro! Changes in the delivery pressure, though crucial to each appliance cannot be determined by visually watching a burner flame. Too high gas pressure will damage many appliances, while too low of a delivery pressure will result in improper combustion and inefficient appliance operation.

By carefully evaluating your technical expertise, learning and gathering a resource library of sorts for those items on your coach, acquiring the proper tools and parts and most importantly, having the right attitude, you may be just the candidate to experience the fun of maintaining your investment for your leisure enjoyment. Of course it could just as well be your full-time home we've been discussing. In any case, it is hoped that major repair costs are avoided and total enjoyment is realized from the experiences of working on your own motorhome. And remember, RVing is more than a hobby, it's a lifestyle!

RV Absorption Refrigeration Basics

While the typical residential refrigerator is more like an air conditioner since a mechanical compressor is utilized, the RV absorption refrigerator remains a mystery to many. It is probably the most perplexing of all the LP-burning appliances found in the typical RV today. Understanding the theory of absorption and “absorbing” why it takes heat in order to make cold can be mysterious even for the most engineer-like amongst us. The usual result is to simply shake our head and grab another cool beverage from the fridge. But by grasping a basic view of the theory of absorption and understanding the importance of leveling, ventilation, and cleanliness, the RV refrigerator can provide many years of RVing enjoyment and independence. Let’s take a look at the absorption refrigerator by first examining the heart of the refrigerator, the cooling unit.

A typical RV refrigerator cooling unit consists of four major components; the boiler, condenser, evaporators and absorber. The unit is sealed and pressurized and is non-field-repairable. The internal contents of the sealed absorption system include water, liquefied ammonia, hydrogen gas and sodium chromate, the chemical used to line the internal pipes to protect them from the corrosiveness of the ammonia.

During a typical cycle, heat is applied to the boiler by either an electric heating element or an open LP flame. Water and liquid ammonia begin to boil and ammonia vapor is passed on to the condenser. The water is separated and returns to the boiler section. After condensing back into a liquid, hydrogen vapor is introduced to the liquid ammonia at the low temperature evaporator located in the freezer compartment. In short, heat from inside the freezer is transferred through the pipes of the low temperature evaporator and released to the exterior. Since the absence of heat is cold, the freezer and everything in it becomes cold.

Next, a remnant of mixed hydrogen vapor and liquid ammonia passes to the high temperature evaporator located in the main food storage compartment and the process of removing the heat continues albeit, less assertively. The food storage compartment/high temperature evaporator becomes cold, but not as cold as the low temperature evaporator in the freezer.

Upon leaving the evaporator sections, the weakened ammonia liquid then flows into the absorber coils. Here the hydrogen vapor rises back up to the evaporator section while the ammonia is mixed with water in the absorber vessel, flows to the boiler and the process starts all over again.

From the point where liquid ammonia leaves the condenser until it reaches the absorber and re-mixes with the water, gravity provides the impetus. Off level operation slows the pace and causes overheating in the boiler section. Continued operation in an over-heated condition results in cooling unit blockage when the sodium chromate particles turn to crystal and block sections of internal piping in the boiler. Unfortunately, in RV absorption refrigeration, this process cannot be reversed. The only remedy for a blocked cooling unit is replacement. The lesson – take the time to properly level the RV as demanded by the principles of absorption refrigeration. The bottom line: keep it level, keep it ventilated, keep it clean. Your refrigerator and your wallet will thank you.

But how do we do that, you ask? By applying basic preventive maintenance practices, that’s how. That term, “preventive maintenance,” is probably familiar to your already if you’ve owned an RV for more than fifteen minutes. I’ve said this before; the wisdom of the concept behind the phrase is often recognized long after the fact. Such is often the case regarding the absorption refrigerator. All too often RVers obtain their education the hard way – through trial and error, and mostly by error at that.

The sophisticated systems found in RVs today can be intimidating for the do-it-yourself type unless he or she is equipped with the proper tools, time, and attitude. Also, the incorporation of printed circuitry, electronically controlled gas valves, 120-volts AC, 12-volts DC and LP fuel in one appliance can be somewhat puzzling unless you possess a degree of understanding regarding the operation of such an appliance. Therefore, performing your own RV refrigerator clean and service will require more than just a mechanical inclination; it will also be beneficial to possess an understanding of the operation of your particular unit as well as of the theory of absorption refrigeration. In addition, the do-it-yourselfer must always place safety as the number one priority. With this in mind, always be sure that the LP container has been completely shut off and that all forms of electricity have been disconnected before performing maintenance on any LP-burning appliances. And for the feint of heart, remember, every RV service facility stands at the ready to perform an absorption refrigeration service for you. As a reminder, here are a few items that need annual attention on any absorption refrigerator:

1.  Burner assembly and orifice. Must be accessed, disassembled, cleaned and reassembled.

2.  Flue and flue baffle. If yours is accessible, remove it and clean away the carbon deposits. A specifically designed flue brush may be necessary.

3.  Ignitor assembly. Likewise, the spark probe, ground probe and flame sensor must be free from carbon deposits.

4.  Cooling unit. The cooling unit is accessible through the exterior refrigerator side vent. Vacuum and clean all exposed components and tubing. Inspect and clean the condenser fins at the very top of the cooling unit. Remove any blockages.

5.  Refrigerator receptacle. Check for proper polarity and voltage at the refrigerator receptacle located at the rear of the refrigerator.

6.  Printed circuit board contacts. Clean and preserve the contact strip on the printed circuit board and all other electrical terminals.

7.  Main LP regulator. Be sure it is adjusted to 11.0 inches of water column and that the RV is LP leak-free.

8.  Storage/non-use. After the camping season ends, be sure to thoroughly clean the inside of the refrigerator completely. Remove all food and wash down all plastic components. Do not use an abrasive cleanser. Block the refrigerator doors open to allow free flow air to circulate inside.

Congratulations! You have, at least, gained an insight into the importance of preventive maintenance, as well as completing RV Refrigeration 101. For the details of how to actually perform an absorption refrigerator clean and service, check out this article.

Cleaning & Servicing the RV Absorption Refrigerator

The common term, "preventive maintenance," is applicable in any number of industries today - the RV industry included. Unfortunately, the wisdom of the concept behind the phrase is often recognized after the fact - for instance, when it comes time to repair, or even replace, the absorption refrigerator in a recreation vehicle. All too often RVers obtain their education the hard way - through trial and error, and mostly by error at that. How many RVers have been known to exclaim, "I sure didn't realize that refrigerators for RVs were that expensive," or "You mean there is something that has to be maintained on an RV refrigerator?"


Contrary to the belief that since absorption refrigerators have no moving parts they require neither attention nor service is the very real fact that many RVers are paying for repairs that could have been avoided had "preventive maintenance" been employed.

Most RVers understand that roof seams, caps, vents and antennas must be sealed periodically to keep the moisture out. It is also common knowledge that RV holding tanks must be flushed out occasionally to prevent blockages. Likewise, all propane gas appliances must be serviced periodically in order to avoid costly repairs and to ensure that they operate at peak performance throughout the RVing season. It is likely that the absorption refrigerator is the most visible, most used and yet, the least understood of the appliances.

For most RVers, the fact that absorption refrigerators require heat to produce cold is baffling enough in and of itself. This article is not intended as a treatise regarding the principles of absorption refrigeration, (refer to this article for that info), rather, it is intended as a discussion of the technical methods used by RV service organizations today in performing the maintenance task traditionally known as the refrigerator "clean and service." In many cases, astute coach owners who possess a bit of technical know-how can perform some of these tasks.

The sophisticated systems found in RVs today can be intimidating for the do-it-yourself type unless he or she is equipped with the proper tools, time, and attitude. Also, the incorporation of printed circuitry, electronically controlled gas valves, 120-volts AC, 12-volts DC and propane fuel in one appliance can be somewhat puzzling unless you possess a degree of understanding regarding the operation of such an appliance. Therefore, performing your own RV refrigerator clean and service will require more than just a mechanical inclination; it will also be beneficial to possess an understanding of the operation of your particular unit as well as of the theory of absorption refrigeration. In addition, the do-it-yourselfer must always make safety the number one priority. With this in mind, always be sure that the propane tank has been completely shut off before performing maintenance on any propane-burning appliances.

What tools will be necessary? Aside from the normal assortment of basic hand tools (those every RVer should carry anyway), several specialty tools will be required to perform a thorough clean and service on an RV refrigerator. These special tools include a thermocouple tester, a polarity tester, a volt-ohm meter, and a flue brush, all of which are relatively inexpensive items that can be ordered or purchased locally. Once obtained, these tools could theoretically pay for themselves within a short time.

A manometer will be used by a professional RV service technician to measure the line pressure of the propane gas system. A vapor pressure between 10 and 14 inches of water column must be maintained in order for every propane appliance designed for use in a recreation vehicle to function at its maximum efficiency level. The manometer is used to monitor the regulator setting to insure that the pressure is set correctly. The industry standard for the pressure is 11 inches of water column (W.C.). Some RVers may assume pressure is measured in pounds per square inch (PSI), but the pressure required by propane system on any RV is so low that a smaller unit of measurement must be used. Translated, 11 inches of water column is equal to .4 PSI. In other words, it's the amount of pressure required to raise a vertical column of water 11 inches high. A standard u-tube manometer is 100 percent accurate since it is an actual tube filled with water and marked off in increments of inches.

The thermocouple tester is used to check the effectiveness of the thermocouple on the refrigerator, if it indeed has one. Most modern RV refrigerators will not be equipped with a thermocouple. The tester can also be used in testing any propane appliances that relies on pilot ignition. This tester can be ordered through any reputable RV parts store or service facility.

The polarity tester is useful prior to plugging any coach into shore power. The tester will assure that the campground wiring is correct. (Of course, this is assuming that the coach wiring is correct to begin with.) The polarity tester simply plugs into any 120-volt AC receptacle inside the RV. For the purposes of this article, it should be plugged into the same receptacle as the refrigerator. A series of three lights (light-emitting diodes, or LEDs) will indicate whether the circuit is correctly wired; if it is not, the tester will identify exactly how it is miswired.

A small, inexpensive volt-ohm meter should be included in every RVer's tool kit. The multimeter has so many uses that it is not possible to list them all here. For the purposes of this article, the device is used to measure the AC voltage at the refrigerator receptacle and also to check the battery voltage at the fridge. These tests take only minutes but could eliminate the frustration of downtime during a trip.

The last specialty tool that is necessary is a flue brush. The flue brush is used to clean the flue assembly of the boiler portion of the cooling unit at the rear of the refrigerator. This brush can be obtained from most automotive supply stores and parts houses. Although not likely labeled specifically as a "flue" brush, it is a round, cylindrical brush with a long wire handle. It has a diameter of approximately three-quarter inches. Unlike the other specialty tools, this one will be applicable only for servicing the refrigerator.

How much time will it take to perform the refrigerator clean and service? Allow two to three hours to do a thorough job. Be advised, however, that this process may take longer with some refrigerators, especially when performed the very first time. But this is usually mandated by the manner in which the refrigerator has been installed.

As a general rule, for correctly installed refrigerators, it's likely to take between two and five hours. The refrigerator should be cleaned and serviced at least once each RVing season, as should the other propane appliances - the furnace, the water heater, and the range. If exposed to dusty or sandy destinations, or if stored in such an area, it may be necessary to clean and service the refrigerator more often. At times, lack of use can be more harmful to propane appliances than abuse.

The three most common causes of propane-related problems with correctly operated absorption refrigerators are dirt, (see photo above), spider webs and inactivity. Notice the stipulation "correctly operated." We are all aware that correct leveling and efficient ventilation are essential to the proper performance of the refrigerator. An entire series of problems could develop when these areas are neglected, but that's a different story altogether.

So, how do you perform a clean and service? With tools in hand and a positive "can do" attitude, are you ready to begin? Not quite. Now is the time to study the operator's manual, user's guide, parts breakdown, and/or service manual for your particular brand and model refrigerator. Try to familiarize yourself with as much literature pertaining to your particular unit as possible. One of the biggest mistakes that even many professional RV technicians make is rushing into a job without enough product knowledge to support their efforts. Don't make the same mistake. When you are confident that you are able to recognize and locate such components as flue baffles, burner orifices, and heating elements, and when the propane container has been completely shut off, then you can proceed.

Cleaning and servicing your refrigerator will involve some degree of disassembly and/or partial removal of the unit, which will usually be mandated by the type of factory installation. For instance, if the gray water holding tank pipe extends upward through the roof and is situated against the burner box at the rear of your refrigerator - which happens - then it will be necessary to partially remove the refrigerator to gain access to the components. If it is necessary to partially remove the unit, disconnect the flare fitting for the gas line at the rear of the fridge and remove all of the screws that secure the unit in the compartment.

At this time, one would be wise to install a flare plug in the gas line, for two reasons - as a safety measure, in case someone inadvertently turns the gas back on, and also to keep dirt and dust from entering the open end of the gas line. Ordinarily, a 3/8-inch flare plug will be required. You'll also likely need to remove the mounting screws that attach the fridge to the cabinet. Once the refrigerator is loosened, it can be slid into the coach hallway by pushing from the outside. Slide the unit only far enough to allow for access to the burner area components. If the burner area is readily accessible without moving the refrigerator, the time required to complete the job will be greatly reduced. Most of the time, the latter will be the case.

The burner assembly should be completely removed for inspection and cleaning. Remove the burner orifice and allow it to soak in carburetor cleaner, acetone, or a like solution. Set it aside to air dry. Inspect the burner carefully. Look for cracks or warping, especially at or near the primary inlet holes if the burner is so equipped. Overheating caused some earlier model burners to warp, thus interfering with the normal process of mixing air with LP and resulting in improper combustion. This particular phenomenon has been all but eliminated by virtue of newer unit design.

After the orifice has dried, inspect the it carefully, preferably through a magnifying glass. The fact that the orifice has been soaked and air dried does not guarantee that it is clean and free from obstructions. The spider webs that are commonly found in burner orifices can be incredibly strong and stubborn. Their presence will be detected only with the aid of a magnifying glass. UNDER NO CIRCUMSTANCES should you insert any object - drill bits, broaches, paper clips, needles, etc. - into the orifice opening. Because these orifices are made primarily of brass or aluminum, (some older refrigerators had orifices made of rubies!) they are fairly soft, and the opening could easily be distorted. Were this to happen, the Btu rating and gas flow rates would be affected, and unusual flame characteristics could develop. If the orifice cannot be cleaned, it should be replaced with one of identical size or with an identical part number. Should you determine that you need to replace the orifice, it is recommended that you consult a professional RV technician.

The spiral flue baffle also must be removed and cleaned. It is situated directly above the burner and is located inside the flue tube. The baffle is installed from the top of the refrigerator, and the method used to secure it will vary from model to model. You will notice that the baffle is suspended by a wire to a predetermined height. This baffle height is critical to your particular refrigerator, and care should be taken not to bend or otherwise alter this dimension.

Once the baffle is removed, the next step is to run the flue brush through the empty flue tube to dislodge any carbon deposits and rust that might be clinging to the side of the tube. These deposits could hinder the flue in its task of evenly distributing heat and drawing the flame into the tube. This step can usually be accomplished through the roof vent, or by partially removing the refrigerator as discussed earlier. In some instances, especially when working with coaches that have curved sidewalls, it might be necessary to remove the entire refrigerator.

Before performing the next step, you must determine which type of unit you have. If your refrigerator is one of the electronic ignition types with an automatic reignite feature then it will be necessary to clean both the electrode and the thermocouple, which are situated directly above the burner and positioned in the flame. This electrode is the flame sense probe, which through normal use can become coated with a deposit of carbon, thus preventing the printed circuit board from doing its job. Clean the probe and the thermocouple by brushing them lightly with a fine-grade steel wool pad. When properly cleaned the probe and thermocouple will appear brighter.

If your refrigerator has an older, thermo-electric safety valve, just a thermocouple will be positioned in the flame. This thermocouple is designed for use with the flame failure safety valve. Should the flame be blown out accidentally, the flow of LP will stop. It is a good idea to clean the tip of this thermocouple, as described above, to insure proper operation. When heated, the thermocouple actually produces voltage that energizes an electromagnet situated in the safety valve. As mentioned earlier, this style of flame failure safety device is not found in modern RV refrigerators.

At this point you should check the thermocouple if your unit has one. Insert the thermocouple into the tester. Heat the tip of the end of the thermocouple that you just brightened by holding it in a flame, and make sure that it holds the magnet of the tester. Thermocouples do fatigue and can weaken; so, if you doubt its effectiveness, replace it.

The next step is not so technical, but it is equally important, as it can have a direct effect on the proper ventilation of the cooling unit. Clean the rear of the refrigerator through the access door on the outside of the coach and possibly through the roof vent. You can either blow the area clean with compressed air or vacuum away the dust and dirt. At this time, conduct an overall visual inspection of the cooling unit area, paying special attention to the condenser fins situated at the uppermost portion of the cooling unit. If the roof vent opening is not protected by a screen, birds and other critters have a tendency to construct their nests on the condenser fins where it is nice and warm. Even when a screen protects the vent, birds will still make their nests up there where it's nice and warm (see photo). This will restrict the airflow over the condenser, causing an overheating situation that could eventually ruin the cooling unit.

In addition to the LP components, one must also check the electrical operation of the refrigerator. Now that you have the refrigerator partially removed and the rear of the unit clean, insert the polarity tester into the 120-volt AC receptacle used by the refrigerator. Plug the coach into shore power to determine whether the polarity is correct at the receptacle. If the tester indicates anything other than the correct polarity it will be necessary to isolate and correct the discrepancy. Disconnect the shoreline and contact a qualified electrician or technician to troubleshoot the problem; unless you have adequate training for dealing with alternating current, please leave the troubleshooting to a qualified individual. You can also check for proper voltage at this receptacle by using the volt-ohm meter. Likewise, measure the amount of battery voltage present at the electrical connection at the rear of the unit.

Servicing the new refrigerators that utilize printed circuit boards involves an added maintenance step. First you will have to gain access to the board where it connects to the multi-plug. Remove the connector and clean the board contacts with a common pencil eraser. This will remove any corrosion or residue that could possibly cause a poor connection and result in erratic performance and improper cooling. (Editor's note: some experts are of the opinion that if the circuit board if working properly it should be left alone). This line of thinking would agree with the old maxim "If it isn't broke, don't fix it."

It is now time to reassemble everything. Insert the flue baffle into the flue tube, and make sure that the flue extension is secured properly if so equipped. Reassemble the burner orifice, the burner tube, and any other portion of the burner area that you removed, doing so in the reverse order in which you disassembled them. If the refrigerator was partially or completely removed during the procedure, now is the time to reinstall it. Be sure to replace all of the screws that were removed. Reconnect the gas line (which will usually necessitate the use of two wrenches), taking care not to twist any portion except the flare nut itself. Now mix up a solution of dish detergent and water. (Do not use detergent that contains ammonia, however, as it has a detrimental effect on copper tubing.) Now, turn the valve on at the propane container and brush or spray this soapy solution onto the flare connection at the back of the unit to check for leaks. Before you go on to the next step, determine that no leaks exist.

The final step in completing your refrigerator clean and service will benefit all of your LP-burning appliances. The LP pressure regulator must be set at 11 inches of water column. (Review the section at the beginning of this article concerning manometers.) It is recommended to take the RV to a pro shop to have a Certified RV service technician perform a timed, pressure drop test to insure no LP leaks exist anywhere in the RV.

Review. Let's review the primary steps performed during a refrigerator clean and service. Doing so will enable you to double-check your work and to insure its completeness without sacrificing the safety factor. If you have any doubts at any time during the procedure, stop and review. Consult the literature to confirm the location of any of the components mentioned for your particular brand and model.

Step 1: Completely turn off the LP at the tank.
Step 2: Partially or totally remove the refrigerator as necessary to gain access to the components.
Step 3: Remove, disassemble, and clean the burner assembly and orifice. Blow dry with compressed air.
Step 4: Remove the flue baffle. Clean the baffle and the flue tube while the burner is removed.
Step 5: Clean and brighten the thermocouple and the flame sense probe or ignitor probe, depending on how your unit is equipped.
Step 6: Test the thermocouple if so equipped.
Step 7: Inspect and clean the rear of the cooing unit, especially the condenser fins.
Step 8: Check for the proper polarity of the 120-volt AC receptacle used for the refrigerator.
Step 9: If so equipped, clean the printed circuit board contacts using a pencil eraser.
Step 10: Reassemble and reinstall all components and the refrigerator itself.
Step 11: Turn on the LP tank and check for leaks.
Step 12: Have the LP pressure set to 11 inches water column.

The final test will be to light the refrigerator in the propane mode and observe the burner flame as it is pulled into the bottom of the flue tube. The flame should be a bright blue with a possible tinge of orange at the very top. It should also be centered directly under the bottom of the flue tube.

Congratulations. You have successfully completed a professional refrigerator clean and service. Hopefully you have gained an insight into the importance of preventive maintenance, as well as the satisfaction of knowing that your refrigerator will be operating at peak performance. And remember your refrigerator will last longer if this periodic maintenance procedure is performed every RVing season.

RV Heating System Maintenance

Maintaining the RV Heating System

If you are wont to travel in your coach during the chilly fall or early spring months, or if you are a serious winter RVer, then you fully understand the importance, convenience and satisfaction of having a fully functioning RV heating system. If not, spend an involuntary cold night in temperatures near freezing or below without heat and you’ll soon wish you did have that understanding! Unlike the cozy warmth of a well-insulated and heated conventional home, the typical RV lacks the depth or robustness of residential-style insulation and the advantage of multiple layers of construction materials separating you from the rage of a cold wintry night.

All too often I receive frenetic correspondence from coach owners suffering from a malfunctioning furnace, stuck in the midst of their travel, relying perhaps on a small inefficient space heater, shivering under a heating blanket, wondering what they might do. At that point, my sage but simple advice would be to add another blanket! However, with a little forethought and a few preventive steps (performed now, before Old Man Winter awakens from his respite), you can enjoy those crisp mornings and evenings in comfy warmth, year after year.

 Over the course of RV history there have been a few different types of heating systems employed, but today’s coaches are equipped typically with at least one, if not a couple of direct-spark forced air furnaces or a hybrid system using hydronic heat for both hot water and comfort heating. Earlier coaches were outfitted with radiant heaters, often better quantified as gravity heaters, or in the case of much smaller RVs, catalytic units. Catalytic is still a viable option for the smaller pickup campers and towables even today.

Other antiquated combo permutations that date back to the 1970s include a combination heater/stove/oven, (Duette), and a heater/water heater amalgamation, (Thermal Twin); both nightmares to service because of their compactness and individual quirkiness. I’m sure the younger RV technicians today are dumbfounded when one of these old combo units rolls into the service bay!

The first thing to understand is that all recreation vehicle LP-burning appliances, for optimum performance, require some degree of annual maintenance. Just read any user’s guide from any RV appliance manufacturer and it will often state, in so many words, that very sentiment. And because of its design and operational characteristics, regular maintenance of the RV heating system is a must.

Today’s larger rigs can enjoy never-ending hot water and multiple heating zones provided by hydronic heating units. Hydronic heating systems provide a continuous supply of hot water for the fresh plumbing system plus comfort heat for the interior. Employing a diesel-fired burner or a propane burner, combined with 120-volt AC heating elements, these types of  “on-demand” systems are much appreciated and handy for those slightly chilly mornings. The diesel or propane burner can be bypassed using heat supplied by an electric heating element, thereby conserving on-board fuel.

About the only regular maintenance required by the owner is to keep an eye on the level of the 50/50 (water/anti-freeze) solution in the reservoir tank. Additionally, diesel units require an annual cleaning of the fuel nozzles and a new fuel filter, while the propane-fired units require an annual cleaning and servicing and delivery source pressure testing like any other propane appliance. Aside from checking the coolant level, most all other maintenance tasks are usually performed by a trained RV service technician.

But because of their sheer numbers, the main focus here will be the forced air furnace; by far the most popular choice among coach manufacturers today. At the root level, a forced air furnace draws in fresh air from outside the vehicle, mixes it with propane and burns it in a sealed combustion chamber (a firebox to all the old-timers). A blower then blows interior air over the heated chamber and into the living portions of the motorhome through a system of ducts or in the case of some smaller Class C motorhomes and travel trailers, directly out of the front of the furnace grill (blow-through design).

Most of the supplier manufacturers use this same design strategy. They may employ slightly different components and possibly a different sequence of operation, but by and large, most follow this same basic premise.

From a comprehensive annual maintenance standpoint, a detailed furnace clean and service procedure involves removal from the coach, partial or complete disassembly, new gaskets and a full bench evaluation; all outside the realm of the typical RVer.




In addition, a three-fold testing process of the main propane pressure regulator and distribution system (including setting the correct delivery line pressure) is also performed by the pros. But from a user’s standpoint, there are tasks the average RV handyperson can perform that will be most advantageous to preserving the integrity of the RV heating system. Four key areas come to the fore:

Four Key Factors

·       Cleanliness

·       Voltage

·       Ducting

·       Return Air

Cleanliness

A clean furnace is a happy furnace. A trite statement? Perhaps, but true. As air moves in, out and around the furnace, dust, lint and other pollutants in the air will naturally accumulate. Too much accumulation and furnace failure is all but guaranteed. Each furnace is typically equipped with two blower wheels or squirrel cages; one to bring in fresh air to mix with the propane, and one to “force” the air over the heated chamber and push it through the coach ducting to the interior living sections. Excess dirt and lint wedges itself inside the blower assembly, essentially weighing it down.

In a normal sequence, the spinning of the main blower wheel closes a device called a sail switch (so named since this small electrical switch is outfitted with a large “sail” or paddle that catches the air moved by the blower wheel). Even though adjusting the wall thermostat actually initiates the heating cycle, it’s the closing of the sail switch that starts the internal electrical sequence of furnace operation. 

If the blower wheel is weighted down with excess dust and lint, (see photo), it will not spin fast enough to close the sail switch (also called an “air prover” switch, by the way). It “proves” the fan is spinning fast enough, bringing in enough air to support combustion. Too much weight, the slower the spin; the slower the spin, the sail switch does not close. An open sail switch; the furnace fails to ignite.

Here’s where to start: With the thermostat in the off position, the LP container service valve completely off and the furnace at room temperature, vacuum in, around and about the innards of the furnace. It will likely be necessary to remove a front cover or access panel to expose the main furnace assembly. In the photo shown here, it will be necessary to remove the aluminum plenum to gain access to the main furnace unit.

If you have compressed air available, while vacuuming, blow out all internal sections of the furnace. Be sure to wear the appropriate eye protection, as dust and dirt will certainly be blown about. The goal is to keep the insides of the furnace assembly as clean as possible. Wipe all surfaces down with a damp shop rag.

Where the circuit board is easily accessed, take the time to clean the board contacts. At a minimum, use a pencil eraser to brighten the contact strip, or better yet, use an electrical cleaner/preservative to chemically remove oxides from the contacts. (Check out this product used by the RV Doctor). At the very least, unplug then plug the connector in a few times. Oftentimes, just a simple “scraping” of the terminal contacts by plugging in and unplugging will restore a heating cycle. 

If the wall thermostat is the older mechanical type, it is still possible to clean and preserve the contact points as you would the circuit board above. There are multitudes of these simple, bi-metallic types out there. If yours looks the one in the photo, it will be necessary to remove the clear plastic cover to expose the two contact points.

Cleanliness of the warm air ducting is also crucial. Some heating systems incorporate a central, manifold ducting system either in the floor or the ceiling. Others simply have individual ducts running above the floor, under cabinets, through partition walls to each major section of the coach. Regardless of the type of delivery ducting in your rig, remove each register and vacuum as far into each duct as possible. Take care not to rip or tear the 4-inch round flexible ducting, if so equipped. The duct in this photo, discovered during an annually cleaning procedure, turned out to be the perfect location for mice to nest! Not only a fire hazard, it certainly contributed to erratic furnace operation.

On the exterior of the RV, inspect the intake and exhaust vents carefully. Use a flashlight if necessary. If the coach has been inactive for a period of time, it’s common to find mud daubers or wasp’s nests inside the cozy confines of the vent tubes. Blockages in the intake tube can result in an overly rich fuel mixture, creating operational faults. Blockages in the exhaust tube can result in overheating, short cycling of the furnace and pose a fire hazard. Apply compressed air to the fresh air intake while covering the exhaust tube with a running vacuum cleaner.

Voltage

Probably the number one cause of flawed heating cycles in forced air systems today is low battery voltage. Furnace fan motors can create a relatively large amp draw on a malnourished battery bank. Add the excess weight of filthy blower wheels and current usage ramps even higher.

When dry camping, the minimum voltage requirement for most all 12-volt DC forced air furnaces is 10.5-volts DC, measured at the furnace. Conversely, when plugged into shore power, running off the converter output, excessively higher than normal DC voltages (above 13.5-volts DC), can create their own palette of problems for the delicate components found on some circuit boards. Maintaining a properly charged battery bank is critical for optimum furnace operation. Low voltage will cause the blower wheels to spin at a reduced rotation. Remember that earlier progression? Low voltage; less blower speed. Not enough blower speed and the sail switch will not close, regardless how clean those squirrel cages may be! Maintaining a healthy battery bank assures you’ll have enough current on hand for the heating system.

Ducting

Aside from the cleanliness issue mentioned above, for those coach owners with individual runs of 4-inch flexible ducts, inspect and straighten all sharp bends or turns whenever possible. Shorten any lengths that appear too long. One of my pet peeves about the way some RVs are produced centers on how some installers simply snake excess ducting back and forth under cabinets rather than taking the time to cut them to the proper lengths. Excess duct lengths will eventually create an overheated situation within the furnace housing and prohibit sufficient heat delivery throughout the living sections. Thankfully this is usually not a concern for floor or ceiling ducts.

Also realize that furnace manufacturers mandate a minimum requirement for the number of ducts, based on the BTU rating (size) of that particular furnace. Take the time to look up the requirements of your furnace and ensure the heating system is sufficiently ducted. I’ve seen the simple addition of another duct eliminate a short cycling condition of a seemingly faulty furnace. That said, I find it altogether too common for inexperienced service technicians (or owners) to blame a furnace component (and the furnace manufacturer by default), for a comfort-heating failure caused by something other than the appliance itself. An informal poll once found that the clear majority of “faulty” circuit boards returned to the factory under warranty were actually fault-free; absolutely nothing wrong with them. Trust troubleshooting/repair procedures only to Certified or Master Certified service technicians.

Return Air

Perhaps more important than an unobstructed heated air duct, a clear path of return air to the furnace enclosure is nothing short of a mandate. A literal “breathing” appliance, the forced air furnace must also inhale fresh breaths of return air as the warm air is circulated throughout the RV in order to operate optimally. You’re probably aware of at least one interior vent located near the furnace compartment, such as in this photo of one under a dinette seat. This is the pathway of return air back to the furnace compartment.

Some coach owners mistakenly install a filter in this vent space; a definite no-no. Unlike a home heating appliance, there should not be a filter installed anywhere in the path of the return air. Additionally, never stow gear or supplies in the furnace compartment. Aside from a fire hazard, it may inhibit the path of the necessary return air. Just like the required number of ducts, furnace makers calculate just how much volume of return air is necessary for their unit to operate properly. The size of the return air grill is further deduced to ensure the return air passage meets the minimum number of square inches of free-flowing air as specified for that particular model of furnace. In some cases, coach manufacturers may even modify the cabinetry to meet these minimum requirements.

In this photo it appears the furnace compartment door is cut too short. Actually, the decorative grill work restricted the return air flow (reducing the number of square inches through the door), to the extent that this gap below the door was necessary to bring it back within spec.




So as the approaching fall months lure us out to see the beauty, proactive coach owners will be diligent about having clean heating system components. They will also maintain a healthy battery system in order to power the furnace properly. Additionally, they will have inspected their ductwork for obstructions. And you know they will certainly not store cargo in the furnace compartment or otherwise block the path of return air.

Keep the above four Key Factors in mind and in practice, and you too can enjoy many years of warmth from your motorhome heating system. Remember, RVing is more than a hobby, it’s a lifestyle!

##RVT763; ##RVT867

Preventive Maintenance Help for RV Electrical Systems

Ponder for a moment just how many items on a modern recreation vehicle are powered or energized by some form of electrical current. The vast majority of the propane-burning appliances and quite a few of our other amenities are indeed electrical in some sense. Because of the advances in electronic applications, gone are the days of “overriding” the system or “by-passing” the controls of analog devices. Today, without a healthy 12-volt battery system it is nigh impossible to even light the refrigerator or operate the furnace let alone find that satellite, make those ice cubes or spin those disks (CD and DVD, that is).

Whether we take into account high voltage or low voltage, battery power, inverter output, shoreline, generator power or solar power, each circuit that uses electrical current involves a power supply of some type, a resistive unit of some type and a method of delivery of some type. This treatise is purposed to bring to your attention not only problems that may sometimes wreak havoc on your RVing travel plans, but to also bring to the table a solution, a preventive cure that will help minimize those problems, if not eliminate them altogether.

The method of delivery alluded to above is usually facilitated by the use of electrical conductors or wires. Batteries are “wired” together; the appliances are “wired” into the system, the converter “wires” the AC system to the DC system, etc. In a perfect world, these wires run, unabated, from the power supply to the electrical product and many times back again. The ending points for most of these wires involves some method of termination. Some are connected to screw-type terminal blocks; some are attached using crimped-on ring or spade terminals. 

Many are connected to a plastic multi-plug encasing many wires at once which then connects to another multi-plug or slips over thin, edge traces on printed circuit boards, similar to those in the photo here.




 
Virtually all LP appliances, roof air conditioners, monitor panels, generators, converters, radios, inverters, etc., will all use some form of a multi-plug connection. Therein lies the bugaboo. At any point where a wire is terminated and connected to a device, there is also the probability of electrical contamination manifesting itself over time; contamination that includes metallic oxides and thin layers of chloride film.

We’ve all seen the worst of neglected battery terminals, which seemingly have living green and yellow organisms growing around the terminal wing nuts. Granted, many of us would indeed take the time to clean those battery terminals, most likely because the neglect is easily visible. But how many of us would take the time and spend the effort to ensure the circuit board contacts are clean and bright on the appliances, or that the shoreline cord contacts are clean, etc. What about the umbilical between the truck and that fifth-wheel trailer behind you? The fact is, many of the ills associated with erratic LP appliance operation and battery charging and discharging, just to name two areas are directly attributable to contaminated contacts on the printed circuit boards or at the multi-plug connections. I would wager that the majority of electrical symptoms are a direct result of corroded and oxidized contact points at wire terminations. And most are avoidable.

It has been written and proved many times over that the physical and chemical changes in the surface condition of electrical or electronic connectors are the primary causes of degraded performance of components and equipment. Add dust, soot, smoke and other gunk that hangs in our atmosphere and strange discolored films will form on the contact surfaces impeding the flow of electrons. Oftentimes the result is erratic operation of appliances, less than pristine battery charging, blown fuses, sticking relay contacts, poor electrical grounding and bonding, etc., amid other intermittent ills often blamed on the battery or other components. 

I’ve seen LP appliance printed circuit boards replaced erroneously when the cause all along was simply an oxidized contact strip on the edge connector. Technicians, unfortunately, often fail to inspect these important contact points and are lulled into a false sense of accomplishment when the new circuit board fixes the problem. Fact is, installing the new board simply scraped away some of the contamination enough to make a better contact; albeit temporarily. Unless the process is stopped, that new board will be diagnosed as “faulty” soon enough also. The same, temporary result would have been effectuated by simply unplugging and plugging in the old board a few times. 

Oxidized contact surfaces as well as chloride films, (prevalent in coastal communities especially), indeed require periodic attention. Cleaned and treated annually, most electrical dysfunctions can be avoided by effectively ridding contact points of such contaminants. So what’s the solution? There are many contact cleaners available, but most only apply a physical “washing” to an area that is predominantly in need of chemical attention. Here’s why:

Oxides, sulfides and forms of chloride contamination physically attach themselves to the thin layers of the contacts on most printed circuit boards. Though more evident with gold plated contacts, still the thin traces of RV appliance boards are negatively affected and become “blistered” to the point of causing added resistance to that portion of the circuit, (see photo above). This added resistance simply impedes the performance of any electronic function and can be the cause of intermittent operation. The technical term for this blistering is called dendrite corrosion, but the result is that the contact portion is greatly reduced, almost insulated to a degree and erratic operation of that appliance is sure to follow and only get worse as time goes on. Simple contact “cleaners” may wash away dirt, dust and grime, but they prove ineffective at removing oxidation and surface sulfides because these tough contaminants, remember, actually attach and become an integral part of the contact metal. The only true method of eliminating these contaminants is by chemical action and reaction. 

Enter some amazing products by CAIG Laboratories Inc. DeoxIT, specifically, is formulated to literally dissolve and remove these oxide blisters by chemical action. After treatment, a thin residue of organic make-up is left behind which coats the contact area thereby protecting the surface. Additionally, DeoxIT contains additives that prevent the loosened oxides from reattaching, ultimately eliminating them through the mechanical action of unplugging and plugging the board back in a few times. 

According to their Product Information Sheet, DeoxIT’s unique properties allow it to work on stationary and moving contacts and connectors with both similar and dissimilar metals. It will even migrate to an untreated contact, (such as a new, replacement board), when it connects to the previously treated connector plug. See if you can tell the difference between the “before" photo above and the “after” photo below. 

Take the time to check a couple of the printed circuit board contacts on your propane appliances. If you see any discoloration on the contacts, it is in need of treatment. Visible discoloration means severe oxidation has already taken place. It will only be a matter of time before erratic performance of that appliance will rear its ugly head. And, according to Murphy, it will usually happen at the most inopportune time. 

I have tested the advantages of DeoxIT and used the product for a few years now and have observed a definite increase in effectiveness of the devices I’ve treated. Not restricted to just RV appliance circuit boards and other multi-plugs, I’ve used DeoxIT on every battery device I regularly use; even the batteries for the digital camera that shot these photos, my iPhone and assorted flashlights, etc.

As a musician, I’ve even treated all the gear I use when playing live. CAIG Laboratories also offers a nifty package of lint-free wipes, swabs, applicators and cleaning brushes that will fit just about any application you may require. All serious RVers should consider adding DeoxIT to the tool kit. Because as you know, RVing is more than a hobby, it's a lifestyle!