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We are saddened to announce the passing of Gary Bunzer on April 17, 2020. We hope the RV Doctor website will continue to provide helpful information for you. Thank you for your interest and support for the RV Doctor - Debbie, Heather and Gretchen

Monday, January 1, 2001

"Technically" Choosing Your Next RV

By Gary Bunzer

So you’ve been RVing for a while and are seeking to upgrade to a larger or different or more sophisticated RV. You may even be considering your first RV purchase. You’ve perused and studied many articles and websites over the past few months on how to “choose” the recreation vehicle of your dreams. You’ve attended seminars, interviewed friends and family, and even reconciled every possible camping scenario to finally narrow the field of possibilities down to your own version of the Final Four; those RVs you would consider for purchase or to trade up to. Now what? Toss those names into a hat and hope for the best? Why not compare your short list from a more technical standpoint; specifically from a preventive maintenance point of view? Perhaps a quick review of the different systems, and what to look for at that level, is in order. It just may be the difference between two or more seemingly similar RVs. Here’s the point; not all RVs are created “technically” equal.

If you have done your homework and indeed read those articles, you obviously know which type of RV will suit your needs and budget, so this article is not designed to help you choose between a motorized and a towable RV. It is intended, however, to bring to mind some technical variances that may make one brand a better choice over another of the same type. This can be extremely helpful if you are a tinkerer, handy with tools and enjoy performing much of your own maintenance. Working on or maintaining your own rig can be very rewarding. And all RVs require periodic maintenance. The ease at which one can access and service those technical areas may make performing maintenance practices easier, less expensive and more fulfilling.

Some coach builders, sadly, look only to economics when choosing which products to include in their models. Cheap, imported products may be legal and available, but to whose advantage is it to equip any RV with products simply based on price alone? I think you know the answer to that one! Kudos to those manufacturers who actually peer beyond the initial sale and consider what might be in the RV owner’s best interest further down the road. Thankfully some manufacturers do this and outfit at least a few models in their line with exceptional products, even if it costs a little more or takes more time to build. Below are a few questions regarding some areas you may just want to consider as you pare down your recreational candidates.

One caveat; some of the items I mention may be beyond the scope of the casual RVer or first-time buyer and therefore may sound confusing or impossible to accomplish. Simply take from this article what you feel comfortable applying. In some cases, especially when buying from a private party, I always suggest a pre-delivery inspection (PDI) be performed by a certified RV service technician prior to the consummation of the sale. Check out this short Q&A. When buying from a dealer, a PDI will be performed (hopefully), by the selling dealer. Always retain a copy of the PDI sheet and be sure to ask the dealer about some of the items below if they appear beyond your current sensibilities.

Note: You’ll also find a few hyperlinks (as above), mixed throughout this article, so take a few side trips and click on these related links. There may even be links within these links so take your time! Ready? Here we go!

The 12-Volt DC System

* Batteries - How accessible are the batteries? Can every cell on every battery be easily accessed? Remember, the astute RVer checks the electrolyte level, the specific gravity and cleans and protects the terminals regularly. Envision getting your hands and tools into the battery area on the coaches you are currently eyeballing. Will you be praising or cursing that task after the purchase?

Did the manufacturer install cheaper hybrid RV batteries, or true deep cycle batteries? What about the method of separating the automotive battery system from the RV battery system if you’re considering a motorhome? Is there a “smart solenoid” or an isolator installed in between the two systems? Or just a simple, electro-mechanical solenoid relay common to the lesser coaches? What about a battery disconnect system? True, many of these better products can be purchased in the aftermarket, but when they come already installed from the factory, that’s a good thing!

* Fuses & Circuit Breakers - Are all the 12-volt fuses and breakers located in one convenient location, (possibly two for motorhomes), or must you search around for myriad, maverick in-line fuses behind hidden panels? Are the fuses labeled? The technical advantage goes to that manufacturer with a keen eye toward organization and order of the 12-volt fuses and circuit breakers.

* Battery Charger - Inspect the charging converter or charging inverter installation very closely. Is there adequate ventilation to keep it cool? Or is it buried somewhere behind a barely-accessible panel? Is it installed per the manufacturer’s specifications? You should get a copy of the installation instructions. How sophisticated is its technology? Does it employ the latest charging algorithms such as three-stage charging? Is the charging output adequate for the size of the battery bank to which it is connected? Correctly sized battery chargers will be equal to about C/5 of the amperage rating of the battery bank; where C is the total capacity of the bank, divided by 5. A 300-amp battery bank, for example, should have a 60-amp battery charger in order to optimize that system. The question is, did that manufacturer choose to go with state-of-the-art or simply settle for middle-of-the-road?

* Professional Neatness - How tidy are the DC wires and cables routed and secured? A coach that exhibits neatly tied and routed conductors exemplifies care and a pride in workmanship. Look closely at the multitudes of those crimped-on wire terminals found throughout any RV. Give a tug on a few of them. Do any pull loose? Now consider the twisting and wracking the RV goes through while traveling down the road. Hmm? Quality crimps are a must for the active RVer or full-timer. Crimped connections further protected by shrink tubing score high on my tally sheet.

* Documentation - Is there a wiring diagram or a schematic provided for that 12-volt DC system? And is it truly reflective of that particular coach? In other words, is it accurate? Having an accurate ladder diagram or schematic for any RV is a dollar-saving advantage if troubleshooting and repairs are required in the future. Time spent by the pro technician “ringing out” a bunch of circuits can become costly in a hurry! An accurate schematic or wiring diagram is a cost-saving short-cut when troubleshooting.

Does the coach come with all the installation instructions, owner’s manuals and user’s guides for all the 12-volt components on the RV? Having the installation guides provides an opportunity for the RVer to verify if the inverter was installed correctly, for instance. High scorers on my manufacturer list ship all the paperwork for every device installed on that RV. Hopefully in a nice, neat owner’s manual and/or in digital format.

The 120-Volt AC System

* Circuit Breakers - Are they clearly labeled and is the distribution panelboard (breaker box) installed correctly? Is it properly bonded and grounded? Is it conveniently located or do you have to crawl on the floor to get to it? With the coach de-energized, remove the cover on the breaker box and inspect the innards. Are the conductors neatly routed within and well-secured to the breakers and buss bars? Or does it look like a rat’s nest or a plate of black and white spaghetti? Is there enough slack in the black wires to allow easy removal of the circuit breakers? You can tell a lot about the craftsmanship at that manufacturer by looking in some of these rarely accessed areas.

* Receptacles - Are there enough of them? And in the locations you will need them? As an example, to be code compliant, there must be a receptacle on each side of the galley sink if the countertops on each side are at least 12-inches wide. The last thing you want is to be forced to drag an extension cord across the coach just to plug in a reading lamp!

* GFCI - You’ll be testing it every month so it should be easy to reach. Does it protect the exterior receptacles? You may have to rely on the service department to ascertain that one. High marks again for coach builders who label all GFCI-protected circuits and receptacles so guesswork is not required.

* Shoreline Cord - Is it a quality, US made brand or did the manufacturer resort to a cheap import? Is it embossed with the ampacity? Is it adequately secured as it enters the RV? Will it be long enough to reach the campground pedestal at your favorite campsite? If the shore cord enters the RV on the side of the coach, it must be at least 25-feet long. If it enters at the rear of the RV it must be at least 30-feet long. Did that manufacturer get it right?

* EMS - Energy Management System. It’s an expensive add-on after the sale; and great when factory-equipped. You’ll obviously be paying for this one way or another, but coach designers who factor in this device are forward thinking and customer appreciated.

* Surge Protection - Same as EMS above. Always available in the aftermarket, but a good thing when it comes with one from the factory.

The Fresh Water Plumbing System

* Water Pump - First of all, can you even find the water pump? How easy is it to get to? What about the filter or strainer located between the pump and the fresh water storage tank? The conscientious builders install one; others do not. Is the water pump adequately sized? In other words, does it pump enough water at the rated pressure to satisfy the length of the piping in that RV? Pumps are available in various output ratings. Did that manufacturer size it properly or will you be running low on pressure while dry camping?

* Fresh Water Container - Is the tank well secured to the floor? Is it insulated to keep it from freezing while RVing in the winter? Does it have a properly sized fill vent? Did the manufacturer install a branch tee and include a valve for administering RV anti-freeze for winterization? Some RVs even come equipped with a small tank just for the anti-freeze!

* City Water Inlet - Is it easy to access or will you be struggling to attach the fresh water hose each time you set up in the campground? Did they invest the time and expense to install a filter or screen on the inlet?

* Valves & Fittings - Some coach builders choose to use cheap, plastic fittings and valves in the fresh water system. Others choose to use brass or metallic valves and fittings. Which do you think is preferable? Yep, the brass valves and fittings. Especially near the water heater (see Bypass Valves below).

* Routing of Tubing - See if you can determine how the installers routed the cold and hot tubing throughout the RV. Did they use elbows to make the turns or is the tubing just bent sharply around the angles? You can guess which is best! Is the tubing secured every 4-feet along the wall or floor? Loose piping can vibrate during use and emit numerous, bothersome noises.

* Accumulator - Did they install one? It’s not a requirement, but a great accessory and good foresight by that manufacturer if they did! What about a filtration system? It might be a value-added item, but if it comes stock on that coach, it holds an advantage over that other similar brand of RV that didn’t install one.

* Low Point Drain Valves - Again, access is paramount. All RVs have a cold and a hot low point drain valve; supposedly installed at the lowest point in the fresh water system. Are they? Or were they just stuck somewhere easy to install to comply with the standard? Coach makers that install real valves instead of simple pipe plugs or caps get higher marks! 

* Water Heater Bypass Valves - Most coach builders today install a bypass kit at the rear of the water heater. A bypass kit containing brass or metallic valves is preferred to those using plastic valves. The heat associated with the water heater and the close proximity has caused some plastic valves to fail. Some lesser-expensive RVs may not have a bypass kit at all. Some of the primo coaches mount the bypass valves at an easy-to-access manifold in a dedicated plumbing bay.

It’s a poor indictment to come to the realization that one must be a contortionist, or be forced to dismantle a portion of the RV, or have a trained mouse in the tool kit just to place the water heater to bypass mode for winterizing! Easy access to common plumbing components is a good thing!

The Waste Plumbing Systems

* Holding Tanks - Are they well mounted in a heated compartment or simply hanging below the rig exposed to the elements? Is it possible to gain access to the outlet fittings to check for leaks? Do the holding tanks appear to be well secured? Do they hang too low, especially when positioned behind the rear axle?

Is there a dedicated holding tank just for the toilet? Though it is permissible for gray water to drain into the black holding tank, it’s much better if all the gray water drains into its own tank, thereby minimizing the necessity to drain and flush a quickly filled black tank.

Are the holding tanks outfitted with a dedicated back-flushing, fresh water inlet? Though not entirely effective at cleaning or clearing a blockage, they do allow the user to easily fill the tanks when flushing rather than running fresh water through the toilet and down the sinks.

What about the probes for the holding tank monitoring system? Are they through-the-wall sensors or did the manufacturer install a sophisticated, non-intrusive, conductive-type monitoring system? Through-the-wall sensors can be fouled by the tank contents over time; conductive sensor strips cannot.

* Venting - All holding tanks must be vented. Although it’s better that each tank have their own dedicated, through-the-roof vertical vent, it is not a code requirement. The same for vent caps; they are not required, but waste plumbing systems with sewer vent caps and a full-way vertical vent for each tank gets my vote of confidence for that maker.

* Termination Plumbing - Are the dump valves mounted vertically or horizontally? It’s better to have them vertically oriented. Here’s why. Did they install manual valves or the preferred, 12-volt electrically operated valves for easier evacuations? If they are manual, can you easily reach the termination valves? Are they positioned in a manner that permits smooth operation? An RV without extension rods or cables attached to the termination valves is more highly regarded than ones with.

Do the outlets from the gray and black holding tanks terminate at one convenient location? Or must you crawl under a slideout to attach the hose and open the valves? See the advantage of a coach equipped with electric termination valves? Does the attachment point for the flexible sewer hose mandate you twist the adapter onto the waste hub? Or did they install the much improved cam-lock type of attachment? Did the coach maker supply a quality sewer hose or simply a cheap plastic hose that will develop pinholes if you touch it or look at it sideways?

* P Traps - Are they all easily accessed? Take a careful close look at that tub/shower installation. All P traps require maintenance unless the manufacturer installed the highly regarded HepvO sanitary valves in their stead. They cost a little more to the coach builder, but they are superior to P traps and are a benefit to the RVer. Those RV builders that go the extra mile with the seemingly small stuff, impress me.

* Drain Plumbing - Inspect the slope of the drain lines under sinks and cabinets. Do any expect the draining water to flow uphill? They must be adequately supported every 4-feet.

* Toilet Rinser - Again, not a requirement, but good for the owner if a coach has one already installed at the toilet.

The Propane System

* Propane Container(s) - Is it (are they), properly secured in a dedicated compartment, to the main frame rail or A-frame? Is the main service valve protected from road debris? Is there adequate road clearance below the ASME tank, if so equipped? Is the fill assembly easily accessed? 

* Pressure Regulator - Is it protected from the elements? It may be sheltered by a plastic cover of some type. Is it mounted with the vent portion within 45-degrees of vertical? That’s a code requirement and it’s not uncommon to find an ASME tank and attached regulator with the vent portion positioned incorrectly! Also, be sure it is a two-stage regulator! Hopefully US made!

It dismays me to see the sheer numbers of imported propane fittings and devices installed on some, supposedly higher-end RVs. Again, it’s my opinion economics trumped quality with some of these components. I hold RV manufacturers in higher regard when they do not sacrifice quality for the sanctity of the bottom line.

* Manifold & Distribution Piping - Did the manufacturer adequately support the black iron piping and copper tubing? Is the tubing protected where it passes through the flooring or a wall? Is that transition sealed against moisture intrusion? Ah, the good builders ensure all such passages are leak-proof.

* Flexible Connectors - Are they routed and secured properly? Are any of the propane hoses bent into a crimped condition when attached to a slideout? Check in both the extended and retracted positions of the slide room. It does happen!

* Tubing Connections - Specifically the routing of the copper tubing to each of the appliances. Are the bends dent-free or did they make that turn a little too tightly going into the furnace and did it crimp the tubing, thereby restricting the gas flow? A quick look at the four, propane appliances will either endear you to that brand of RV or turn you off.

* Appliances - All propane appliances require yearly maintenance. Can you easily gain access to the burner area of the refrigerator? Oftentimes, ABS plumbing vents are positioned in the same cabinet as the refrigerator making it necessary to partially or completely remove the refrigerator in order to perform simple maintenance.

Check out the above floor furnace ducting, if so equipped. Did the installer simply snake the excess ducting back and forth under the couch and under the cabinets or do they appear orderly? If long runs of ducting are not cut to the length needed, furnace malfunction is inevitable

Is the water heater installed directly under the refrigerator so that the hot exhaust from the water heater is sucked into the lower vent of the refrigerator? Not a good design. Especially when the refrigerator and the water heater are installed in the same slideout.

Does the entry door of the RV open against the intake/exhaust assembly of the forced air furnace? You can guess what might happen!

Exterior Details

* Roof Sealants - Are all the screw locations on the roof properly sealed against leaks? Every item on the roof; antennas, sewer vents, air conditioners, solar panels, horns, powered vents, roof racks, ladders, etc., are all mounted in some way to the roof. All screw-attaching points are simply a leak waiting to happen. The same with front and rear caps and center seams. The conscientious coach manufacturer will ensure the proper sealants are applied in the correct manner.

I’m a big fan of those makers who use the neatly applied Eternabond tape to joints and mounting flanges for components on the roof, rather than the sloppy looking, poured on, self-leveling sealants. Unless of course the sealant is masked off and neatly applied. I mentioned one of my pet peeves is fit and finish. Neatness of sealants, how they’re applied, how sharp they are trimmed, for example, give me the satisfaction that that factory is conscientious, professional and cares about the consumer.

* Sidewalls - The same thing regarding all the items attached to the sides of any RV. How neatly did they trim the sealants around the windows, doors and compartments? Did they take care when applying silicone or butyl caulk or does it look like a monkey applied it with a three-inch spatula? The quality application of the sealants displays a higher level of professionalism and an appreciative attitude towards the end-user rather than a quick passage through the production line and letting the dealer worry about it at the retail level.

* Undercarriage - Ah, out of sight; out of mind, right? How much detail given to the undercarriage of the RV provides insight into a manufacturer’s attitude towards the end-user. Are all wiring harnesses protected and well secured? Is the frame rusted at any location?

Are all the voids around tubing, drainpipes, wiring harnesses, et al; anything penetrating the bottom of the RV fully sealed against critter infestation and moisture intrusion? Any gaps will permit unwanted guests and moisture easy access. The conscientious builder will completely seal the undercarriage to prohibit such invasiveness.

Weights & Balance
Take special notice of the mandated weight label inside the RV or on the exterior. Look specifically at the amount of cargo weight you can carry. You just may have to leave your bowling ball collection at home when you travel. Some coaches have plenty of storage capacity for all your recreational gear; others may become overweight as soon as you stow the canned beans!

Weight distribution is a valid safety concern and those weight labels deserves a little studying when comparing coach A to coach B. Become familiar with all the weighing terms. Check out this important article to get started.

Obviously there are many other technical areas that could and should be considered such as access to the fluid reservoirs in a motorhome or the ease at which electric trailer brakes can be adjusted, etc. This article, though not all conclusive, should provide a little insight into yet another method of “choosing” your perfect RV. Remember, RVing is more than a hobby, it’s a lifestyle!


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If you are in doubt or do not feel comfortable about a procedure, do not continue. Simply call your local RV service facility and make an appointment with them. The advice, recommendations and procedures offered by the RV Doctor are solely those of Gary. They do not necessarily reflect the opinions, procedures and recommendations of our sponsors or advertisers.