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.

Dead Battery on Towed Vehicle

Hey Doc! Every time I tow my GMC Sonoma 4x4 pickup more than four hours without stopping to start the truck for a while, my battery is either completely dead or just barely turns over the engine. Is there a fuse I can pull during towing to reduce battery usage?
Tim, (Reno, NV)

 

Tim, a lot depends on how your GMC was wired for towing and of course, what type of on-board equipment you are using, I. E., auxiliary braking device, lube pump, etc. If all the power for turn signals, stop lamps and running lights originate with the motorhome, as they should, and no on-board power is required by the pickup, then the simplest method would be to install a battery disconnect switch for all circuits contained in the truck. This can be accomplished with a simple knife-blade manual switch or a simple electric solenoid mounted near and connected to the battery on the truck. Both are available at any well-stocked RV accessory store. 

Either device will enable you to fully disconnect the truck battery while towing. I do recommend breaking the circuit on the ground side. However, it’s possible there is a drain on that battery caused by the tow wiring. Some circuits may require diodes to prohibit current draining or bleeding while towing. Without seeing the wiring or the methods employed as it stands right now, I’d only be guessing. I’d recommend a trip to your local RV service center to check out the existing wiring configuration and possibly have that bothersome drain eliminated. I’d hesitate removing any fuse until it can be ascertained that that circuit (protected by that fuse) is not required by the truck while towing.

Pimpled RV Interior Paneling

Our motor home is 2 years old and we have discovered what is best described as small pimples on the interior wallboard under the passenger window. I'm guessing there is about 100 of them that are 1/16" wide. Suspecting this is a water leak I removed the interior window trim and sprayed water on the roof and window looking for a leak and found nothing. What could this be? Thomas (Lodi, OH)

Thomas, you are probably correct; such marks are typically caused by moisture reacting with the glue on the wall panels. As a starting point, removing the window trim was the right course of action. If you are sure there is no source of water entry at the window or the roof above the window then the water is likely entering somewhere else and eventually seeping towards the window, where it finds its way to the inside of the coach. A good place to start a detailed inspection would be exterior moldings or trim pieces mounted close to the window. Inspect them very carefully for open seals, rusted mounting screws, etc. Also inspect the entry door seals and any other fitment attached to the sidewall that is at the same level, or likely higher, than the window. Remember, water seeks its own level, so the leak could literally be anywhere above the window. Excessive moisture can migrate laterally to a lower location before it is actually manifests itself. Water leaks can be extremely difficult to find and need to be caught early to avoid an expensive repair. Search meticulously and thoroughly and you should find it. RV repair facilities can be a last resort if you simply cannot locate the entry point of the moisture. Some will be equipped with ultrasonic devices that can locate water leaks in a relatively short time. If all else fails, take it to a pro shop. Be sure to use a sealant that is applicable to the material(s) you'll be applying it to once you located the source.

Holy RV Rubber Roof

The rubber roof on our RV has hundreds of little tiny holes in it. They are through the thin white stuff and show black at the bottom of the hole. We have already gotten the roof very clean. Do we need to seal these? We bought this RV used and I am afraid we got taken.
Lila, (Longview, WA) 

Lila, I wouldn’t get too concerned just yet. It’s doubtful those black spots are actually holes in the EPDM rubber material. The rubber roofing membrane consists of a couple plies or layers. I believe you may be seeing the bottom ply and not all the way through the membrane. Older rubber roofs had a definitive black layer on the bottom and it’s usually the thickest layer. The fact that the uppermost layer is showing signs of weathering and oxidation is normal. Normal oxidation is a condition due to the disintegration of surface binders and elastomers, usually by normal weathering. The result is that surface chalking actually removes a portion of the white rubber. This is a normal occurrence and you should not be concerned about the direct effect on the rubber itself. However, if the degree of the wear is severe enough, more drastic measures may need to be taken. For instance, it may be time for a new membrane (most membranes will last 10 – 12 years). Or perhaps a coating of a liquid EPDM material called Liquid Roof, produced by Pro Guard Coatings (www.proguardcoatings.com) can be applied. A lot depends on how old the roof is and to what degree the oxidation has occurred. I would suggest a visit to an established RV service center for a detailed inspection and analysis. Search around for a qualified shop. RV collision repair shops are usually a good bet…or shops that regularly re-roof RVs. It does take a certain expertise. I would try the Liquid Roof product if at all possible, before resorting to a brand new membrane. It’s quite easy to apply.

No Output - RV Water Heater

I am having problems with the hot water heater which is both gas and electric. The tank fills up and the water gets hot but when I turn on the hot water at any faucet all I get is cold water. I checked the valve and it is open on the water heater. There are three valves; one is the cold water feed and one is for hot water and there is another pipe the runs in-between the cold water pipe and the hot water pipe. When I turn this valve off I get hot water for a second or two and then I lose all pressure and nothing comes out. But when I turn this valve back on I get water pressure, but only cold water.Any ideas?
Gerald, (Mansfield, OH)

Gerald, this appears to be a problem with those hot water bypass valves. The pipe that runs between the hot and cold water lines is there to put the water heater in bypass mode for winterizing. It allows the antifreeze to cross over from the cold water lines to the hot water lines without filling the water heater tank. This valve must remain closed for normal operation. It is open only for winterizing when the other two valves are closed. Since the hot water outlet is at the top of the water heater, you won’t get any pressure in the hot water line unless the water heater is completely full. You mentioned that the water tank fills up, but I suspect it may not be completely full when you are checking it. Make sure that the valves on the cold inlet and hot outlet are totally open and that the crossover pipe valve is fully closed. The water heater can then fill normally. 

It can take quite a while for the water heater to completely fill up. You’ll know it’s full if you have water emitting from the pressure and temperature relief valve on the front of the water heater. Once water flows freely from the P&T valve, begin opening the hot faucets one at a time. It will take a few minutes to purge all the air out of the lines. Once you have water flowing freely from every hot faucet, light the water heater or turn on the heating element. After the water heater cycles off, you should be able to have hot water at each hot faucet as soon as the cold water clears. This could take a few minutes of running the hot faucet. If you still do not have hot water flowing through the system, there could be a blockage in the water heater, one of the fittings or kinked tubing coming out of the heater and further troubleshooting will be in order. It’s also possible that center crossover valve is faulty; not truly closed even though the handle indicates it is closed. If you have plastic bypass valves, it might be a good idea to upgrade to the more robust brass valves.

Skimpy Motorhome Molding

One of the most troublesome things I have found to maintain are the exterior moldings which are used to seal the seams along the edges of the motorhome siding. Many times there is only the smallest portion of the siding being covered by this molding and as we know the severe movement of all parts of an RV can allow the siding to become dislodged from under the molding. Are there aftermarket moldings which allow for more coverage of the siding? I have an RV where only a 1/4-inch of the siding was covered and after the road trips and movement of the siding due to expansion/contraction from the sun, etc., is now unsecure and subject to water infiltration from rain events. Why do manufacturers seem to skimp on such a vital piece of moisture protection? I regularly reapply sealants but if the molding isn't sufficiently large enough to overcome normal movements of the siding what suggestions do you have for remedying this dilemma?Eddie, (Smyrna, DE)

Eddie, I hear you; I’ve seen your exact problem on many RVs over the years. Thankfully not so much lately as most coaches now have radiused corner sections. Basically it is due to a poor installation of the sidewall skin and/or the roofing. The sidewall skin should extend fully to the top of the roof, before the roof material is applied. The roofing, then, folds over the edge and is stapled or secured through the sidewall material and into sidewall itself. If the installers cut the sidewall material too short, the overlapping roof material won’t quite cover the top of the sidewall skin. If they cut the sidewall and the roof covering too short, there’s nothing that will protect that top edge. Some edge moldings used back then only extended down the sidewall a short distance. And like you noticed the wracking of the coach along with the temperature changes results in the loose skin and what amount to an open funnel for rain water. The only fix I can suggest, short of replacing the siding, is to install another piece of flat molding and position it just below and tight up against the existing molding. Prior to securing, re-staple the sidewall skin to the sidewall structure; it’s okay even if they show since the new flat molding should be at least ¾ or 1-inch wide. Be sure to use a butyl caulk strip behind the new molding piece. If you get a matching insert, you probably won’t notice the double molding once installed. Unfortunately, this is simply a cosmetic approach to a repair.

Motorhome Fuel Tank Sending Unit Surgery

I have a Triple E motorhome with Chevy 454 engine. The gas gauge does not work and I have been told the sending unit requires repair. The problem is apparently the gas tank has to be removed and there is no one in our town that will do that. There is a mechanic that wants to take out the bed in the back, the water tank and go through the floor to find the sensor! Do you think this is okay to do or is this mechanic crazy? Cathy, (Sault St. Marie, ONT)

Cathy, indeed the fuel tank probably needs to be dropped, or at least partially removed in order to replace the sending unit. But I can’t believe your mechanic! His suggestion can be likened to going through the mouth to take out the appendix! Granted, it’s a cumbersome job, but most RV repair centers should be properly equipped with a portable fuel pump and container to remove the fuel, drop the tank, replace the sender, reinstall the tank and pump your fuel back in. It’s really not that difficult unless some structural members need to be removed first. Even in that case, it’s just part of the process. 

Now that said, some motorhomes have an access plate under the carpet, right on top of the sending unit. I cannot remember if your coach has such an access, but I would press and feel all around the carpeting in that area of the RV, just over that fuel container and see if you can feel any type of cover plate or mounting screws. The carpet pad and/or the carpeting may be too thick, but it’s worth a try. In any event, any qualified RV service shop should be able to easily perform the replacement. They should also be able to verify that indeed the sending unit is faulty before going to that extreme. I’m so glad your mechanic is not a dentist; I’d rather him not cutting into my stomach to fill a cavity in my tooth!