Our P-Traps Froze!

We were recently caught in that arctic freeze that inundated the Northeast. We went to ready our RV today for a trip next week and found our sink drain p-trap in the bathroom frozen shut. We had to pour hot water down the sink in order to melt what appeared to be a solid block of ice. My husband tried to take apart the p-trap at the joint, but it would not budge. Was anything damaged by this? How can we avoid this in the future? We don't winterize the RV since we use it during the winter some. We're sure it had something to do with the recent very cold weather system that came through. Thanks for your helpful hints! Mary D., (New Brunswick, NJ)

Wow! You were in some seriously cold weather Mary, as was much of the country of late! I have one word for you; Florida! Seriously though, I'm sure many p-traps probably froze during the recent cold weather in those parts of the country. Unless proper precautions are taken, it probably happens more often than most people realize!

One of the problems with the standard p-trap in an RV is that they require regular maintenance. Unlike p-traps in residential or commercial sink drainage systems, the RV p-trap is not used as regularly, therefore diligence on the RVer is necessary. Some of the drawbacks to RVs equipped with standard, run-of-the-mill traps is that the water lock must be maintained at all times. Without that sealing water lock, odors from the holding tanks can rise up and into the living portions of the RV. And keep in mind, it is code-compliant (and fairly common) for some sinks to be plumbed to the black, solid waste holding tank. So odors from either tank may have a direct conduit to the interior of the RV if you do not keep a watchful eye on the level of the water in each trap. (How many of you with RVs equipped with a combo washer/dryer have ever checked the p-trap associated with the washing machine drain?)

Because we don't use RV sinks as often as the sinks in our homes, it's also plausible for the water in the p-trap to lose its sealing ability due to common evaporation. Also, as RVs round corners, especially on curvy mountain declines, the water in the trap can be swished out of the trap, again creating that free pathway for odors to enter the living areas.

I've even seen instances where the lavatory sink was plumbed to the toilet holding tank and simply flushing the toilet caused the water in the trap to be siphoned out of it, enough to negate the water lock.

For RVers who are prone to actually using the coach during cold weather, it's not a bad idea to pour a 1/4-cup of RV anti-freeze down each sink drain every few days to ensure the water does not freeze if that sink happens to sit idle during a cold snap. As an alternative, windshield washer fluid, which is less expensive in most locales, can be used instead of RV anti-freeze. 

But to be 100% worry-free, and 100% odor-free, I recommend replacing all the RV p-traps with a HepvO waterless sanitary valve. You've probably heard me mention the HepvO in a video or seminar somewhere before, but I can't say enough good things about this unique plumbing device. It is 100% maintenance free and eliminates the possibility of holding tank odors from ever entering the living space of the RV. It also provides for more storage space under the sink since it can be installed vertically or horizontally and can positioned as high up as the sink will allow. It's hard to argue against any serious RVer who can appreciate the positive attributes of the HepvO. Another good thing is that it is easily installed by the average handyman. I'd encourage you to take a look at my video regarding the HepvO valve. You can view it right here.

I doubt the severe cold snap you encountered damaged anything in the drainage system, unless of course you see leaks when running water through that drain, but I can guarantee you'll never have a freezing problem again, since the HepvO waterless sanitary valve is not dependent on a water lock to prevent odors from coming into the RV, hence the "waterless" part of its name. Check it out... Click here to order your HepvO valves. 

##RVT773; ##RVT879

Foul Odor From RV Batteries

On a recent camping trip, we were connected to 30-amp shore power. During the night, our CO alarm went off. Since there was no stove or furnace operating, I felt the alarm was defective. I did notice the coach battery compartment was warm to touch. Later when entering the coach from outside, I noticed a foul odor that I couldn't identify. We drove the motorhome back to Cincinnati and hooked it up to shore power (30-amp). This morning I went to the RV and the CO detectors, (2 of them), were going off. I opened the battery compartment and found the batteries and cables very warm and the same foul odor. Is it possible that the batteries are producing carbon monoxide poison? Fred N., (Cincinnati, OH)

Fred, the charging and discharging of the batteries will not produce carbon monoxide, but unless charged properly they will off-gas a foul odor consisting of a combination of hydrogen vapors and sulfuric acid. Rapid charging or rapid discharging of the batteries will also produce an abnormal amount of heat as well; as you’ve noticed. 

I’m not sure what brand of CO detectors you have, but it may be possible they are sensitive to the boiling of the electrolyte that is probably taking place at the batteries. It's also possible the detector has become contaminated or is at the end of its effective lifespan. Check the "Replace By" date tag or label on the back of the detector or in the literature provided. Most detectors will need replacing at about the seven year mark, but check your date code to verify.



Without having the benefit of running some tests and taking some measurements, I’d hazard a guess that the AC-DC converter is overcharging the battery bank every time you are plugged into shore power. Be sure to keep a close eye on the electrolyte level in each battery in that bank until you rectify the problem. It can literally boil the water right out of the electrolyte, produce heat and off-gas the hydrogen and sulfuric acid. This is the odor, I believe, you are smelling. 

In my opinion, many stock charging converters are not sophisticated enough or engineered with circuitry designed for the complete and proper charging sequences necessary for optimal charging of commercial grade deep cycle batteries. Many have a propensity to overcharge the battery bank. I’ve always suggested investing in a dedicated three-step battery charger and allowing the converter to convert and have the battery charger, charge. Multi-stage, processor-controlled chargers can be user-set to accommodate any type of battery so it knows how to charge, when to charge, and at what current and voltage so that overcharging does not happen. 

But be sure to verify the integrity of the CO detectors! Never compromise the safety factor! You'll want to update your detectors if they need replacing. They sounded off for some reason!  

##RVT830;##RVT910

RV Holding Tank Evacuations Optimized!

When you are at a campground that has a sewer hook up and you are only going to be there over the weekend, should you leave your tank closed and dump when you get ready to leave or can you leave it open and just clean up? Pam S. (Waco, TX)

Pam, in order to practice optimum waste management, it is always best to keep both holding tank valves fully closed until the tanks are as full as possible. Most experts recommend at least 3/4 full. If you do not fill it to that level during the course of a weekend, it’s still best to fill them with fresh water to at least the 3/4 mark (completely full is best), before evacuating. There’s a couple of reasons for this. The fuller the tank, the more velocity you’ll have during the evacuation which helps to completely flush all the contents; especially for the solid waste tank. Plus it gives the through-the-wall monitor probes a better chance of staying cleaner. The sludge/tissue/residue on the sides of the tank are less likely to dry out and become rigidly stuck when you fill each tank almost full prior to evacuating.

Another reason for closing the valves, specifically the liquid tank valve, is to avoid your RV becoming a virtual vent for the septic system of the campground itself. See my explanation under number 3 below. If you happen to have an internal venting problem or dried out P-traps within your RV, odors can further proliferate.

Here’s a proper dumping procedure that was recently featured in an article I wrote for FMC Magazine.

Correct Waste System Evacuation Procedures
1. Always wear disposable protective gloves when handling any waste system component and be sure to wash your hands thoroughly afterward.

2. Connect the sewer hose. Begin by inserting the nozzle end of the hose into the campground sewer inlet or dump site, and open the valve on the nozzle. Walk back towards the termination assembly on the coach extending the hose only the distance required. Always avoid snaking a full-length hose back and forth on the ground. If more hose is needed to reach the coach, simply attach an extension hose when necessary. All quality hose makers will have extension hoses and connectors. To complete the connection, remove the protective cap or plug on the motorhome end and attach it to the termination outlet. Be sure to maintain the proper slope of the drain hose from the termination outlet to the sewer inlet.

Known as the “first in - last out” rule, inserting the sewer end first and removing it last will guarantee no release of waster water and avoid further contamination on the ground. Note: this is only applicable if the hose has a positive shut-off valve on the sewer end and a cap or plug on the coach end.

3. Only evacuate a holding tank (black or gray) when it is over 3/4 full. Yes, contrary to what some veteran RVers may tell you, this means leaving the gray valve fully closed while in the campground. Filling each tank to a level above the 3/4 mark before evacuating will ensure you’ll have enough volume (and velocity), to thoroughly drain the tank and flush the hose.

Here’s another reason for keeping the gray holding tank valve completely closed except during evacuation. Ever walk through a beautiful, scenic campground and catch a whiff of sewer odor wafting through the park? Kinda ruins the moment, right? All coaches with the gray tank valve in the open position (sewer hoses obviously connected), are simply acting as a direct conduit to the park’s sewer system. Each coach becomes a mini-vent of sorts, in parallel with the septic system of that campground. No wonder sewer odors still abound in the nicest of destination sites.

Follow the logic; a large septic system in a campground will have fundamental venting designed into it, but with numerous RVs connected to that system with their gray tank valves open, odors can rise up through the park’s septic system, through the sewer hoses of those coaches, through their empty gray holding tanks and up the vents of those holding tanks. Remember, it may be your gray tank, but it’s the campground’s black and gray odors coming up and through it. The only problem with this scenario is that the gray tank vents on the RVs are a lot closer to the ground and more prominently located than the park sewer stack so odors are more noticeable. By keeping the gray tank valve closed until the tank is almost full, you will eliminate the localized venting of the campground sewer gasses at your particular site. The more RVers who follow this precept, the less likely we’ll have to endure septic odors in and around the campsite.

4. Evacuate the black tank first. This is pretty much standard procedure and something most all coach owners are aware of, but it’s worthy to mention it again.

After the black tank empties flush it out with a large amount of fresh water when connected to city water. Simply keep flushing the toilet while the termination valve remains open. If you opt for the Polychute or Drainmaster hose, monitor the cleanliness of the water through the integral Clear-Vu fitting as it drains. There are other clear fittings available for the bayonet-type hose adapters as well. When the draining water is relatively clear, stop flushing, close the gate valve and cover the bottom of the black tank completely with fresh water.

Permanently installed holding tank spray kits are available in the aftermarket that attach to each holding tank thereby allowing fresh water to be directly induced into the tank after dumping, but I’m hesitant to drill mounting holes into holding tanks. Plus I like to flush all components of the waste system including the toilet, sink drains, etc., so I prefer to simply flush the toilet and run water through the sinks.

5. Evacuate the gray tank last. After the black tank has completely emptied and its termination valve properly closed, open the gray tank valve and empty that holding tank. Be sure to rinse this tank as well. Dumping the gray tank last utilizes its liquid contents, as well as the fresh water induced after dumping, to help wash away any solid waste that may remain in the sewer hose.

6. Drain the sewer hose. After both tanks have been emptied for the last time at that location, take the time to thoroughly rinse the sewer hose with fresh water until clear water is viewed through the Clear-Vu fitting on the sewer hose. After closing the gray termination valve, remove the sewer hose from the termination outlet on the motorhome and, if so equipped, secure the plug to the hose and the termination outlet. Then begin “milking the hose.” In other words, raise the hose at the coach end and walk it towards the sewer inlet. Keep raising the hose as you walk, thereby “milking” the hose and emptying it completely of water. Even a properly sloped flexible sewer hose may have residual water and waste particles left inside. These particles will become an odor generator over time, so it is imperative to completely remove as much moisture as possible.

7. After milking the hose and as you reach the campground sewer inlet connection, close the positive shut-off valve on the sewer nozzle and disconnect it from the campground sewer inlet. Remember the “first in - last out” rule! With the cap on the coach end and the nozzle valve turned off on the sewer end, all remaining odors stay inside the hose. Cap the sewer inlet and then stow the hose and add an enzyme-based additive to all holding tanks.

8. Check the P-traps. Unless you upgrade to HepvO waterless sanitary valves, every month or so, look down each sink drain and the tub/shower drain to ensure the water seal is still there. In some waste system configurations, a quickly draining tank can actually cause the water lock to be siphoned out of the trap. You’ll probably have to use a flashlight, but it is essential that a water lock remain at all times. Remember, this is the primary method of preventing gray holding tank odors from entering the interior of the coach. Bottom line; a dry P-trap is nothing more than a shortcut for odors to gain entry into the motorhome.

9. Be sure the toilet bowl contains water at all times. If water eventually seeps past the seal and the toilet bowl empties, it’s time to make an appointment at your local service center. An empty toilet bowl will permit black tank odors into the coach. If water can leak past the seal, odors can also!

##RVT789 

Product Spotlight: HepvO Waterless Sanitary Valve

One of the most common complaints of RVers is the proliferation of obnoxious odors emanating from the waste plumbing system. Nothing can ruin an excursion faster than having holding tank odors permeate the interior of the coach. The first line of defense against invading fumes is the water lock established by P-traps located below the sinks and tub/shower drains.

Long a staple in the plumbing trades, the common P-trap has served us well for many years. There is a downside however, especially concerning recreation vehicle P-traps that are used less frequently than commercial or residential applications. Oftentimes the water seal in a coach P-trap is diminished or lost altogether. The jostling that occurs while traveling, improper siphoning action during highway turns and tank evacuations or simply drying out from non-use can render the water seal ineffective at blocking holding tank odors from entering the living area of an RV. In addition, the P-trap requires diligent maintenance; frequent cleanings and freeze protection are necessary and often overlooked. If neglected, waste residue inside the traps can foster bacteria growth and subsequent odors from within.

Enter a new product, the HepvO waterless sanitary valve. Available in the aftermarket and now found on many coaches right from the factory, the HepvO waterless valve replaces the common P-trap, thereby creating an effective seal against odors while providing additional storage space (who reading this would not appreciate having more room for personal effects?).

This ingenious sanitary valve is constructed with a self-sealing, yet flexible, silicone-derived membrane that allows water to flow through it, but completely closes off when water flow stops thereby preventing holding tank odors from migrating up and through the sinks and the tub or shower. The HepvO is also an effective air-admittance device, which eliminates the need for mandated anti-siphon trap vent devices at fixture P-trap arms.

With no standing water as in a P-trap, the HepvO waterless valve eliminates the possibility of bacteria growth and eliminates the freeze concern and evaporation issues.

Check out this RV Doctor video!

To order the HepvO waterless sanitary valve, click here now!

Dumping RV Holding Tanks

I just completed reading your handout on holding tanks and odor control; very informative! My wife and I are new to the RVing world and we are excited about it but a little apprehensive at the same time. We have many questions, most we don't even know to ask yet! One question on the holding tanks, after reading your article, maybe I missed it, but if we only camp one or two weekends a month for a couple of days each time, do we still wait until the black and grey tanks are at least 3/4 full before we dump? That might mean that our coach would sit in storage maybe two to three weeks at a time with waste in the tanks. Is that okay? Another question on the fresh water tank, would I drain both this tank and the hot water heater after each weekend trip if the RV just sits there? Roger, (Topeka, KS) 

Roger, you should really avoid having that waste lying dormant in the tanks during the weeks between trips, especially in the solid waste tank. If you’re only using the RV on the weekends and it remains less than 3/4 full, simply add more fresh water so that the total capacity of the black holding tank is at least that full prior to evacuating. Dump each tank after every weekend trip. Here’s the reasoning; in order to maximize the flushing velocity, it’s necessary to have the tank filled or almost full. A partially filled black tank can develop tank blockages if there is not enough force to flush out all the contents. This isn’t normally a concern for the gray tank. Just simply evacuate it normally after emptying the black tank. And be sure to run fresh water down through the toilet after draining the tanks to rinse the sewer hose, the valves and the connections. 

The polyethylene water tank and the water heater will not suffer any ill affects during storage periods of less than month if you choose to leave them full of water. But you be the judge; if the water smells odd or tastes stale, then you may have to drain and refill after each use. As you are probably aware, it all depends on the quality of the water you put in there to begin with, right? Many motorhome owners prefer to dump all the tanks, including the fresh water to avoid the added weight while driving.

By the way, the December 2010 and January 2011 issues of Family Motor Coaching Magazine feature an in-depth, two-part article on Waste Management. Be sure to check them out! I go into great detail in all areas of waste containment, odor control and preventive maintenance, including information regarding new products and processes.

Non-Stop RV Refer Operation

I have been told through second hand information that it is better to let an RV refrigerator run all the time, even when the motorhome is not in use. The technician claimed that when the refrigerator is not running that the fumes from the ammonia will cause corrosion and thus will rot the aluminum to the point that it will leak. He claimed that when left running all the time you will not experience the problem of replacing the unit. Any thoughts on this?
Bob, (Sebring, FL) 

Bob, I can’t say I would put much stock in what that technician told you. There are no ammonia fumes associated with the absorption refrigerator. It’s a completely sealed system. Ammonia is corrosive, true, but 90% of all leaking cooling cores are due to moisture intrusion from outside of the cooling unit pipes, typically inside the foam pack area where it is most difficult for condensation and moisture to evaporate. All the tubing in a cooling unit, by the way, is made from steel, not aluminum. Additionally, during the charging process, a chemical called sodium chromate is induced into the sealed system which coats the inside of the cooling unit tubes, thereby protecting them from any corrosive action of the liquid ammonia.

In my opinion, running the refrigerator when not necessary is basically a waste of energy (120-volts electricity or propane), and puts more wear on the system controls than starting it up as needed. The life of the heating element will likely be shortened if allowed to run continuously on the electric mode. Plus when operating on propane, the burner and flue will need to be cleaned more often. If you have a fairly new RV and refrigerator, battery consumption would also be a concern and the constant operation of the circuit board(s) will also take its toll eventually. I honestly cannot see where there is anything to gain and actually more to lose by letting the refrigerator operate non-stop. But that’s just my opinion. 

Basically it goes back to the definition of an RV as put forth by RVIA; it’s a vehicle made for “temporary” living. A switch to a household-type compressor-driven refrigerator, however, would be a viable option for those RVers with full time hookups and no need for LP operation.

RV Fresh Water Chlorination

The water in our RV had a bad odor; a musty smell, so we added some Clorox to the tank and let it set awhile. Now we cannot get the Clorox taste out. What do you suggest we add to get rid of the Clorox taste?
Stacey, (Sacramento, CA) 

Stacey, foul or stale tasting water can not only ruin a vacation but may even be harmful. But the pungent flavor of Clorox might even be worse; like drinking water from a swimming pool! There is usually sufficient chlorine in most city water supply systems for safe storage in an RV, but if foul tasting water persists, it may be necessary to treat the fresh water system from scratch. Of course, the fresh water container only stores the quality of water put in there, so be sure to taste it prior to filling up. Here’s the approved method of chlorinating the entire fresh water system:

1. Drain and flush the fresh water tank; leave empty. Be sure the water heater is not in the bypass mode.

2. Mix 1/4-cup of liquid household bleach (sodium hypochlorite) solution with one gallon of fresh water. (A clean 1-gallon milk bottle works great for this).

3. Pour directly into the fresh water tank.

4. Pour in one gallon of the chlorine/water solution for every 15 gallons of fresh water tank capacity.

5. Top off the tank with fresh water.

6. Remove or bypass any water purification equipment and/or filtering cartridges.

7. Turn on the water pump and open every faucet in the RV, including exterior faucets or showerheads.

8. Allow the solution to pump through the system to the toilet, through the water heater and to every hot and cold faucet at each sink until a mild odor of chlorine is present at every fixture.

9. At the city water inlet, using the eraser end of a pencil, push in on the check valve spring allowing the solution to pump out through the city water inlet until the chlorine odor is detected in the discharge.

10. Close all the faucets and turn off the water pump.

11. Allow the system to stand for four hours. This will chlorinate and disinfect the system, including the fresh water tank, the water heater, the faucets, the complete piping system and all fittings to a residual level of 50 ppm (parts per million).

12. At four hours, drain and flush the system with fresh water once again.

If 100 ppm residual concentration is required or desired, use 1/2-cup of bleach instead of 1/4-cup with each gallon of the solution and let stand for at least one to two hours. Do not allow the chlorinated solution to sit longer than four hours in the fresh water system to avoid damage to some delicate plumbing components found in some water pumps. This is the approved method to be sure bacteria are effectively eliminated. This process should be performed after any period of nonuse or storage, or whenever stale or distasteful water is experienced. 

Since you’ve already put Clorox in the system, you may have used too much. Just keep flushing it out. Fill the tank, pump it through, drain and refill. If the heavy bleach concentration has permeated the plastic piping severely, you may have to keep pumping fresh water throughout the entire system to be sure all the bleach is eliminated. Eventually the odor of the Clorox will subside. There are aftermarket fresh water additives that can be added to the fresh water tank, but those that I’ve tested consist primarily of chlorine elements and I don’t think you need any more of that. I’ve also heard of adding distilled vinegar to the water system. Add about 1-quart for every 5 gallons of water capacity and pump it through the system as you do with chlorine. Let it stand in the system overnight and, as with chlorine, fully flush the system until you are satisfied with the taste and smell. I’ve not tested this method personally, but if the Clorox taste still remains, it just may be a viable alternative method.

##RVT791

RV Holding Tank Sewer Odors

I recently purchased a 2003 motorhome. I have emptied the black water holding tank and noticed the tank is quite odorous still when driving. I do not notice the odor when the unit is parked. Any suggestions on how to correct this problem will be helpful. Elaine, (Elk Grove, CA)

Elaine, the first thing you should do is fully flush out the holding tanks with copious amounts of fresh water. Keeping them rinsed after each evacuation will help minimize holding tank odors. You only state the tank was evacuated, not if you’re adding fresh water afterward. Also, if you’re not yet doing so, only add enzyme-based tank additives to help break up the solids in the black holding tank. But probably the best thing you can do is to replace the existing sewer vents on the roof with Xtreme Vents. 

I believe I’ve mentioned them before, but it bears repeating. These aerodynamically designed roof vents capture the breeze when the RV is standing still and takes in ram air while driving. Xtreme Vents operate on the venturi principle of air being passed over a tube. As air passes over the open end of the vent pipe, it draws air and odors from the tank. This will help eliminate odors by literally “sucking” them out of the tank. This is extremely helpful, (get it?), especially when a 14-inch roof vent is located very close to the sewer vent. The Xtreme Vent will, thankfully, eliminate that design flaw with some floor plans. And remember, there are just as many odors emanating from the gray holding tank as the black tank. I consider it one of the best add-on components available.

Ever Nagging RV Batteries

I own an older Coachman motorhome. I have a problem with the charging system. When I plug the RV into an electric outlet my auxiliary battery becomes overheated (very hot) with a strong sulfur smell. This has happened numerous times and every time I have to disconnect the battery so that it doesn't blow up. I have had the RV to a technician and he removed the converter and had it checked out. I removed the solenoid located behind the battery on the fender and had it checked. Any information that you can provide would be greatly appreciated.
Kevin, (Eveleth, MN) 

Kevin, I’m sure you’ll agree, battery problems seem to ever nag us. The first step in troubleshooting any problem with an RV battery system is to analyze the battery itself. Sulfated batteries simply will not hold a charge and are prone to overheating while charging. The degree of sulfation is also proportionate to its ability to hold a charge. All batteries self-discharge, but sulfated plates quicken the rate. 

See if your local RV service shop has a carbon-pile battery load tester. This test will provide insight to the internal happenings of the battery. Clean and tight electrical connections are also extremely important. Corrosive terminals and faulty connections all lead to early current loss. Don't overlook the negative side of DC circuits as well. 

Additionally, older motorhomes are notorious for employing mediocre or even inadequate charging systems. The alternators and converter/chargers of old did not have the technical algorithms available today for proper and complete automatic battery charging. Rarely did the batteries ever reach full charge unless plugged into shore power for a very long time. Some were quick to reach an overheated charge rate; I suspect this issue with yours. 

Tests should also be performed on the battery circuits to determine if any current loss exists. Some small, parasitic drains are normal, but when current losses approach 700-800 milli-amps, something needs to be rectified. Obviously, a larger drain on a battery is even worse. Any Certified Technician can easily perform this test for you, but if you have a good, quality multi-meter, you can even do it yourself. Consider ordering my video, "Testing the Battery Systems - the Basics." 

There is good news, however. Today there are aftermarket alternators and chargers (available on-lne or at your local RV parts dealer) that increase the RVers ability to extend the electrical life in the batteries. Also, newer battery technology has improved battery performance and has minimized over-charging risks. It should be a consideration for all "serious" RVers of older coaches to upgrade to high-tech batteries, sophisticated three-step chargers and high output automotive alternators. Electrical woes will certainly be minimized and under proper usage, completely eliminated.

Furnace Odor

I have a Duo-therm furnace, model #90130.001 and when the propane tank gets almost empty, the furnace gives off an awful gas odor in the RV. Is there anything one can do to eliminate this odor?
Ned, (Jonesborough, TN)

Ned, the LP odor seemingly emitting from your Duo-Therm furnace when the container is almost empty is not typically attributed to the furnace itself, but rather the level of fuel in the container. A chemical odorant, ethyl mercaptan, is induced into liquid propane during the distilling process to insure that if a leak occurs, the user would indeed be made aware of it.

Liquid propane is inherently odorless and colorless and as potent as LP is, the odorant is added as a safety feature. Since the mercaptan is heavier than the liquid propane, it eventually settles to the bottom of the storage container. When a container is near empty, the percentage of mercaptan relative to the remainder of the liquid fuel is far greater than normal. When LP is utilized in RV appliances as a vapor during this low level situation, some of the odorant can seep into the appliances and become evident to the user.

In furnaces, this phenomenon is usually kept to a minimum since the furnace is a completely sealed system and uses outside air to mix with the LP for combustion. But it can happen since the 900 series Duo-Therm furnace utilizes a different type of burner configuration which forces an extremely rich mixture into the combustion chamber. If any unburned fuel is left inside the chamber at any time during the heating cycle, the smell could be evident inside the RV. You probably do not have a problem as long as you do not smell the mercaptan at other times when the container holds a greater amount of LP. To be sure though, I recommend you have your coach thoroughly leak tested using a manometer.

Crabby Refer Odor

How do you get odors out of the RV refrigerator/freezer? I recently had to leave my fifth wheel trailer and truck at a storage facility for about ten days and the batteries to the truck and fifth wheel died, therefore not allowing the propane to ignite. Needless to say, I ended up with spoiled food in the refrigerator and freezer and no matter what I have tried, I cannot get the odor out (specifically crabmeat). Please hurry with your answer!
Christine, (Orlando, FL)

Christine, for refrigerator and freezer odors some RVers have suggested using open boxes of baking soda and other remedies like placing wadded up black and white newsprint in the freezer and replacing the pieces every day. Or try one or more of these remedies sent to me by readers in the past. (I swear they are all true!)

* wash the freezer using a liquid citrus degreaser

* thoroughly wash the rubber door seal using an anti-mildew solution

* washing the interior with straight bourbon

* unscented kitty litter, changed daily

* cotton balls saturated with vanilla extract to wipe down the interior; leave balls in for a week

* charcoal briquettes placed on paper towels inside the freezer

* spray the interior with rubbing alcohol, let stand and rinse

* four to six ounces of fresh coffee grounds placed in a sock; leave for one week

* peppermint extract placed in an open container

* place a saturated towel of pure Mexican vanilla in the freezer

I'm not sure which is the absolute best cure, but the most often repeated suggestion was using the crumpled up newspaper. Do let me know what works best in your situation. Keep in mind, some odors may indeed permeate the plastic lining of the refrigerator or any rubber component such as the drain tube, door seals, etc. If that is the case either all plastic components will have to be replaced or perhaps a new refrigerator is in your future.

Exasperating Tank Odors

We have had a problem with our Itasca having a sewer smell. The sewer gas build-up is so strong that we had to leave and go to a motel in the middle of the night and it also sets off the LP gas detector. We dumped, flushed, added extra chemicals, bleached, and everything that we could think of. Do you have any suggestions for us?
Shirley, (Colusa, CA)

Shirley, holding tank odors can indeed be exasperating. One important thing to check on your unit; remove the roof vent caps, (many simply twist off), for each holding tank from on top of the RV. Look for an oversized hole drilled through the roof, one that is way too large for the actual diameter of the pipe. I have found that, oftentimes, builders drill or cut such an oversized hole to make it easier to install the plumbing. It is imperative that you seal this gap around the pipe to prevent odors from escaping the pipe, bouncing off the underside of the vent covers and back down into the actual ceiling of the RV. Trapped holding tank odors will simply permeate through the RV and maintain a presence since the gasses will continue to be manufactured in the tank.

For improving upon the design elements of something as nondescript as a sewer vent, you may want to check out a product on the market called the Xtreme Vent; http://www.coilnwrap.com/more/Xtreme-Vents.htm. I'm a big fan of using them on both black and gray holding tank vents.

And rather than masking odors from the holding tanks, I recommend using a biological additive, one that employs live bacteria to literally eliminate the odor-causing molecules themselves. Many suppliers have now produced such an enzyme-based additive. Avoid using any "chemical" in the holding tanks, especially those that contain formaldehyde. Detergents and some ammonia products may damage seals in the termination valves.

Contrary to what even I have expounded in the past, also avoid home brews. Realize suppliers spend lots of money on R&D, so why risk the integrity of the RV waste system for the sake of a few dollars. Once you switch over to the live "bugs," further use of other types of deodorants and/or detergents will likely kill the good bacteria and defeat the purpose.

As for evacuating the tanks, many RVers completely close the black water tank and evacuate when it approaches full capacity while leaving the gray water valve fully open so bath and kitchen water freely drains the entire time. The drawback to this method is that obnoxious odors can and will proliferate and emanate from the gray tank quite rapidly. I support the method of keeping both container valves fully closed and evacuating each when almost full and using the live bacteria additive in each tank.

What's That Smell?

We have a Dometic refrigerator in our RV with a strong smell of ammonia inside and outside of unit. Plus the refrigerator won't cool at all. The motorhome has been parked level for the past few months. This was our first usage this season. What gives?
Jim, (Auburn, WA)

Jim, unfortunately, you have a leaking cooling unit which renders the refrigerator inoperable. The entire cooling unit will have to be replaced. Cooling cores can develop leaks due to moisture entrapment within the foam insulating block. A rupture or crack in the tubing results in the release of the ammonia. If the leak point is situated at or near an exposed section of tubing at the rear of the refrigerator, a bright yellow residue is usually visible. If the leak is in a section of tube hidden by the foam block you may not visibly see it, but any indication of an ammonia smell confirms a leak indeed.

Typically, service centers replace the cooling core with a new or refurbished unit, sending the damaged core back to the supplier to be repaired, recharged and placed back into inventory. The entire replacement can take anywhere from two to four hours to complete, depending on the size of the refrigerator.

Unfortunately, cooling units cannot be repaired in the field - they must be replaced. Not an inexpensive venture, oftentimes RV owners must contemplate a complete refrigerator upgrade versus just the cooling unit replacement. It depends on the age of the refrigerator and how fond you are of your existing unit. On units around eight years or older, seriously consider a complete refrigerator replacement. A new refrigerator will have a new warranty and all new parts. With a cooling unit replacement only, the remaining original components are still aged and non-warrantable. Your local RV accessory store will be able to accommodate either choice you make.

Faulty Cooling Core Redux

I have a 26-foot Class C with an absorption refrigerator. I have just noticed a strong ammonia odor when I opened the freezer door with the refrigerator in the off position. I expect that this is NOT normal. Can you tell me what's wrong and what I am faced with?
Gary, (Carlsbad, CA)

Gary, I hate to be the bearer of bad news, but unfortunately you have a leaking cooling unit. Please see my response to a similar question here .

Annoying Ammonia

Being a rookie RVer, I accidentally did not have my motorhome fully leveled while camping and therefore, I now have a leak in my RV refrigerator. I am getting that wonderful ammonia smell when the door is opened. How hard is it to remove the refrigerator? I live in a small town so would a local mechanic be able to help me? I am guessing the refrigerator is ruined. Will the refrigerator need to be removed right away?
Naomi, (Seattle, WA)

Naomi, obviously because of the leaking ammonia, the refrigerator is rendered inoperable. The entire cooling unit will have to be replaced. Not an uncommon occurrence; cooling units can become internally blocked by operating off-level and a rupture or crack in the piping will result in the release of the ammonia. If the crack is situated at or near an exposed section of piping at the rear of the refrigerator, a bright yellow residue is usually visible. If the leak is in a section of pipe hidden by insulation (the more common occurrence), you may not see it. But any indication of an ammonia smell confirms a leak indeed. 

The first thing to be concerned about is ridding the ammonia smell from the motorhome. Be sure you open all the windows to air the coach out and refrain from using the rig until the odor has been dissipated. Ammonia is quite hazardous.

Typically, service centers replace the cooling core with a refurbished unit, sending the damaged unit back to the supplier to be repaired, recharged and placed back into inventory. The entire replacement can take anywhere from two to four hours to complete depending on the model. 

Cooling units cannot be repaired in the field - they must be replaced. Not an inexpensive venture, oftentimes RV owners must contemplate a complete refrigerator upgrade versus the cooling unit replacement. It depends on the age of the refrigerator and how fond you are of it. On units around eight years or older, seriously consider a complete refrigerator replacement. You will have a new unit warranty and all new parts. With a cooling unit replacement only, the original components are still aged and non-warrantable.

It’s best to let the service center remove the refrigerator and only allow a competent RV service technician perform the replacement. Oftentimes the refrigerator will not fit though the entry door without removing some components and/or the entry door itself. In some cases, the cooling unit is replaced inside the RV.

Messing Meeses

Last year mice got into my RV. This spring I got an electronic mouse repellant and it appears to be working. Here is the problem though; Last winter, they must have urinated in the heating ducts. When I turn the heat on now, this obnoxious odor comes pouring out. I have tried running the heat now a couple of times while out of the motorhome for a couple of hours each time, yet it continues to come out strong when I go back the next time and turn the heat on. Any suggestions?
Cheryl, (Sutton, MA)

Yikes Cheryl! That’s got to be annoying! I’m guessing that there is little you can do to eliminate the odors completely. I once had a cat urinate in an open guitar case and I could never find a product that would get rid of that smell. I eventually got rid of both…..the guitar case and the cat; and not necessarily in that order. Chances are the urine has permeated the insulation inside the ducts and is now permanently entrenched. Adding heated air to the mix by running the furnace only exasperates the problem.

The only cure is to replace that section of ductwork. If your ducts are routed on top of the flooring inside the RV this task is relatively simple. If, however, you have a central distribution ducting system, it becomes more problematic. In that case, first try stuffing crushed-up black & white newspaper pages into each duct as far as you can easily reach and then closing or taping off the ducts for two to three days. Every two or three days, remove and trash those pages and stuff new crumpled pages in there. Repeat as often as necessary. Crushed newsprint has removed fouled food odors from refrigerators in the past, perhaps it can work wonders for mice urine as well. Check with your local pet store also; they may have urine odor products available.

Wish I had better news for you, but animal urine is definitely one of the most difficult odors to eliminate. Maybe some of our members and readers have further ideas. I’ll be happy to pass on any worthwhile suggestions to you.

##RVT927

Frustrating Fumes

When we park our motorhome outside all closed up, my wife and daughter both complain about a smell that burns their eyes and stuffs them up. It has a rubber roof and a slideout. I have washed the roof a couple of times to see if that helps. It seems to be worse on hot days. Any insight into this would be very welcome. Thank you for your help.
Alan, (Ann Arbor, MI) 

Alan, it is quite possible your wife and daughter are experiencing a case of formaldehyde irritation. Formaldehyde is often found in common products used during the manufacture of certain recreation vehicles. Because of its broad adhesive ability and high bonding qualities, formaldehyde is used in the production of pressed wood products, wallboard paneling, and possibly in some furniture and cabinet components. It can surely be a perplexing problem and a definite hindrance while trying to enjoy the RV lifestyle. Simply masking the odor with air fresheners or letting the coach "air out" will not usually eliminate the problem. There has been a rash of recent formaldehyde news of late.

The following steps (as provided by an RV manufacturer), will neutralize the effects of the formaldehyde contamination you are experiencing. Be sure to take the necessary precautions while performing the following procedures. It may be advisable to take your motorhome to a reputable RV service facility and have them perform these steps if your eyes and throat are easily irritated. The procedures outlined here involve the use of aqueous ammonia, more commonly known as ammonium hydroxide. This ammonia, while it will eliminate the formaldehyde problem, contains strong irritants that also affect your eyes, nose, and throat during the fumigation process. If you choose to do it yourself, be sure to wear a protective mask, eye protection and gloves while handling the ammonia. Also be sure to read the first aid instructions that come printed on the ammonia container. You will need approximately one gallon of ammonia.

• First, remove all plants, fish, animals, foodstuffs, etc., from the RV. I would also empty all the drawers, remove bedding and all cooking utensils just to be extra careful.

• Remove all the drawers and open all the cupboards and closet doors. You’ll want the ammonia to evaporate into all areas of the RV.

• Disconnect the motorhome from shore power, but leave the batteries connected. Turn off the LP at the container.

• Drain the fresh water tank.

• Turn the furnace thermostat all the way up so that the furnace fan runs continuously. There will be no heat since the LP container is closed, but the circulating air will aid in moving the ammonia to all areas of the RV. Make sure all furnace ducts are clear and open.

• Close all the exterior windows and roof vents tightly.

• Pour one-half gallon of the ammonia into two wide, but shallow plastic bowls. Be sure to wear the appropriate safety protection. Place the bowls on a flattened plastic garbage bag in each of the two areas of the coach.

• Allow the ammonia to stand and evaporate naturally for a minimum of 24-hours, then open all the windows, doors and vents to rid the coach of any residual ammonia smell.

• The remaining liquid in the plastic bowls can be safely poured down the sewer drain, since it is comprised mostly of water at this point.

• Refill the fresh water tank, reinstall all the drawers and stow your belongings.

There should be no residual formaldehyde present after this fumigation process and subsequent venting of the RV. It may be necessary, however, to daily vent the coach for a week or so to completely rid the RV of any leftover ammonia smell. This should effectively solve your problem.

Waste Management Woes

Our black tank in the RV is plugged up in the toilet tank. We bought one of those back-flushing devices and back washed the tank several times. We took a snake and ran it as far as it would go from the toilet side and still the tank will not drain. The snake seemed to just coil up. Is there something else we could try?

Randal, (Phoenix, AZ)

What is the best method for thorough cleaning out of the sewer holding tank? Maybe like a pump or a back-wash system or an inside flush system?
Darryl (Albuquerque, NM)

Randall and Darryl, if I had to pick just one area where I feel RV manufacturers have let us down, I would have to pick the waste management system. And it extends beyond the limits of the sidewall of the motorhome as well. I also believe the importance of this subject has long been under-evaluated so please allow me to indulge myself for a minute or two. We can all agree that waste managementis probably the least appealing aspect to the RVing lifestyle. But to enjoy the total freedom RVs give us, it is something we must endure.

Thankfully, many RV coach builders have just about mastered the waste containment part by going to full-flow 3-inch outlets on all tanks, including the gray tank, improving the venting, adding better, non-invasive, monitoring systems and installing electric termination valves at the container outlet instead of a manual valve at the end of a long drain pipe. These additions to waste systems have generally made containment and evacuation easier and much safer. And safety is the key when it comes to the health and well-being of RVers! Just ponder the many bacteria, viruses and other disease-carrying critters that must thrive within the holding tanks and termination assemblies of our coaches. But, a serious problem lies between the termination assembly on your rig and the inlet to the dump station or sewer connection at the campground. That gray area (no pun intended), is not governed by any standard! Both entities, the RV manufacturer and the campground, leave that totally up to the discretion of the RV owner. Think about it, that portion of waste transfer, the most vulnerable to spillage, leakage, contamination and disease, is left to the end user; in many cases, a novice RVer with little or no experience in the correct methods of evacuation and transfer.

Here’s what’s baffled me for some time: The RV itself must conform to rigid standards of design and construction and the RV campground must conform to the standards of sewer design and construction, yet the crucial link between those two is not even considered. So your questions are good ones. Let me begin by stating that these are just the opinions of one lone RV Doc and that certainly other solutions may exist. My “best method” starts with using the proper sewer hose. I recommend sewer hoses made from polypropylene (PP) or polyvinylchloride (PVC); the thicker, the better. Look for hoses 32 mil thick or thicker. I’ve field-tested thermoplastic hoses 40 mil thick and those are the best. Avoid hoses made from vinyl. They are prone to pinhole leaks and simply do not last as long as those constructed of thermoplastics. Vinyl hoses also have a tendency to “spring back” to its collapsed/relaxed condition whereby it seems you’re constantly fighting against it to get it connected. The PVC hose, on the other hand, contains an inherent memory and needs only to be extended to the length needed to make the connection.This provides the least resistance to the materials flowing through it during evacuation. I’m also a firm believer in allowing both holding tanks to be filled to above 3/4 full before emptying; the fuller, the better. The more force you have behind the evacuation, the less chance you’ll have of leaving contents behind. Any residual build-up in the bottom of any holding tank will eventually grow to become a blockage. I’m guessing this is your situation Randall.

You’ll notice I said “both” holding tanks above. Many RVers are instructed to leave open the termination valve for the gray tank and simply let it drain continually while connected to the campsite sewer inlet. This practice will leave behind residue that will dry out and lead to odors and possible blockages. That’s right; holding tank odors can emanate from the gray tank as well as the solid waste tank. Fill them both and then evacuate when near full. Additionally, leaving the gray tank valve open all the time disrupts the sewer venting balance within the campground sewer system itself.

Ever notice a waste odor while strolling through the campground? With open gray valves, the campground now has multiple vents (individual motorhomes) spewing odors closer to the ground via the gray vents on the RV. It’s common practice to dump the black tank first, then the gray tank in order to help rinse the solids out of the termination piping and sewer hose. Continue to do this. I also recommend, where practical, to flush each tank with lots of clean fresh water to help rinse away any particles left over after evacuating. You cannot use too much fresh water in this step.

My final recommendation is one you’ll have to sub out. Locate a dealer offering the cleaning services of All Pro Water Flow. This company employs high pressure hydronics (500 – 3,000 PSI) for cleaning the entire interior of each holding tank. Macerators and pumps may allow holding tanks to be evacuated faster while RVing, but the results will not likely be cleaner or more thorough than liberal amounts of high pressure water spraying the entire interior surface of each tank once or twice a year (depending on use). For those holding tanks with internal monitor probes, this process will eliminate those erratic tank readings also! Randall, this service will eliminate your current condition. Since the advent of this service, I no longer recommend the back-flush method wherever possible. Tests have proven that back-flushing is not effective considering the time it takes to do it correctly. Back-flushing, however, is still better than doing nothing at all. It’s my recommendation though to keep all fresh water components far away from any waste system components. So if you back-flush, use a dedicated water hose and stow it with the sewer hose to avoid any confusion between it and the fresh water hose used for the city water connection.

 Another new entry in the aftermarket that will eliminate false monitor panel readings caused by fouling of the in-the-tank probes are the Horst Miracle Probes.

So by starting with good equipment, filling each tank to near-capacity, evacuating fully and flushing out each tank after evacuation and annually having high pressure hydronic cleaning performed,you’ll both be practicing the “best” method of holding tank cleaning possible.

Blind Faith

Our day/night blinds have broken threads. Is there a way to fix or rethread them or should we purchase new ones? Both living area blinds broke only days apart. We also have a musty smell and taste in our water. What could we do to correct this problem? Should we drain our fresh water? My husband has purchased a new filter. I just want to make sure there isn’t something we can do to sanitize the tank.
Pat, (Shingle Springs, CA)

You know Pat, I tried, once, to repair a broken string on those blinds; I simply did not have enough fingers or patience to finish the task. Perhaps one of the many RV outfitter companies can help you with those shades. They regularly handle such soft goods. I have to admit that if it does not have LP, water or current flowing through it, I’m out of my environment. 

As for the water system, you’ll indeed need to drain and flush that fresh water tank. You’ll also need to drain and flush the water heater. It’s not uncommon for odors to develop in the water heater when the anode rod deteriorates beyond 75% or so. Suburban and older American Appliance water heaters are equipped with an anode rod to combat electrolysis. Atwood uses a different type of inner tank material and therefore, does not require an anode.

You can sanitize the fresh water tank and fresh water system by adding regular household bleach to the contents of a full water tank. Simply add 1/4-cup of household bleach, (sodium hypochlorite solution), for every 15 gallons of capacity in the tank. The resultant chlorine concentration will be 50 parts per million (ppm). Pump this through the entire fresh water system; all hot and cold lines. Let the solution stand for a minimum of four hours. Then simply drain and refill the tank with fresh water.

Update! Since this question was published, other posts relating to the day/night blinds have surfaced. To read more about repairing broken blinds, see this post.