Noisy RV Water Pump

My water pump is turning on about every couple of minutes without any faucets calling for water. It is also very noisy and vibrates the pipes down the side of RV. There are no apparent leaks, no kinks, etc. What could be the problem? It did not do this when it was brand new. J., (Mills, WY) 

Judy, you say you have no apparent leaks, but be sure to check carefully for any evidence of moisture inside cabinets, storage compartments, under the coach, etc. If you are absolutely sure no water accumulation exists it might be time to have the water pump itself checked. Some pumps can leak internally, meaning that even though there is no call for water (no faucet turned on), it may have an integral leak.

The pressure switch, built into the pump head, senses a drop in pressure and short cycles the pump. It’s like the pump “burps” for a few seconds. Basically it starts up, quickly builds the pressure and then shuts down. A weak spring in the pressure switch could be at fault. Or possibly a worn seal is not fully shutting off the water flow through the pump head. With an internal leak, there would be no evidence of water accumulating or dripping.

But carefully check all the fresh water plumbing tubing in the RV, including the hot side just to be sure. A cracked fitting anywhere in the system, even though it may not be enough to gather a huge puddle, can still cause a drop in system pressure; enough that the pressure switch senses this reduction and starts the cycling.

One sure-fire way to test the pump is to cap off the outlet fitting right at the pump. You may have to purchase a plug or a cap in order to do this, but by terminating the outlet port of the pump, you’ll be able to isolate the problem to the pump itself, or another fitting or component somewhere in the rest of the system.

After you cap off the outlet port, turn the pump back on and wait. If it still short cycles periodically over the course of a couple hours, there is a problem inside the pump. If the short cycling stops completely, there is a seeping fitting somewhere else in the remainder of the system meaning further troubleshooting would then be in order.

As far as the pump being noisy, be sure it is secured well to its mounting surface. The best location is flat on the floor of the coach. Make sure the mounting screws and rubber isolators are intact and secure. If the fresh water tubing is semi-rigid PEX, it’s advantageous to have a double loop of flexible tubing connect directly to the outlet side of the pump before it attaches to the rest of the PEX tubing, (unlike the photo above). 

SHURflo makes a “Silencing Kit” consisting of a couple flexible connectors and the appropriate fittings. This kit is adaptable to any RV water pump. Ask for Part Number 94-591-01. If the pump is still overly noisy, another option is to add an in-line accumulator. The accumulator invokes a cushion of air and acts like a shock absorber of sorts to soften the vibrations caused by pumping water.

RV Roof Air Conditioner Caused No-Voltage Situation

I recently purchased a 2008 Lexington. I started the generator and after a few moments I turned on the air conditioning unit. While adjusting the thermostat on the air conditioner I accidentally turned it off. I turned the air conditioner back on and immediately I lost the electrical power. Not only power to the air conditioner, but also power to all my 120-volt circuits (TV, microwave, etc). I went to the bath and tried to reset the GFCI. It would not reset. We went to an RV park a half an hour later and I thought the shore power would do the trick. However, in a nutshell, while the generator is running or when I have shore power, I cannot get any 120-volt circuit operating. I did not trip a breaker on my panel box, however I reset all those as well. Where else might a breaker be? Help! Charlie, (Hampton, VA) 

Charlie, your Lexington incorporates an automatic transfer switch to facilitate the automatic switching between the voltage from the generator and the shore power. I realize you’ve reset the circuit breakers on the main panelboard, but also make sure the circuit breaker on the generator itself is not tripped. If that breaker is tripped, and at the same time, the transfer switch relay is stuck on the generator output, you’ll not have any voltage coming in from the shoreline. However, it sounds like the power surge caused by the accidental short cycling of the A/C compressor probably blew the fuse inside the transfer switch or possibly damaged the relays inside. You are apparently not receiving voltage from either source now as evidenced by the GFCI. The coach GFCI will only “test” when voltage is applied to that circuit. You’ll need to locate the auto transfer switch box.

The transfer switch is a large box usually relatively easy to find since the shore power cord feeds directly into it. Trace the shore power cord as it enters the motorhome and you should find it. It may be behind another piece of gear. It will most likely have two other power cables leading to it; from the generator and the converter. 

Once you locate the transfer switch, make sure the shore power cable is unplugged and the generator is not running. Open the transfer switch cover and check the fuse(s) inside. If a fuse is blown, replace it. If not, there could be internal damage to the switch controls and/or the associated relay and you will need to have your system diagnosed professionally. You should have no trouble replacing the fuse, but a Certified RV technician should only attempt further internal diagnostics.

Air Leak on RV Siding

I own a 32-foot toy hauler. Recently on a trip, I noticed air getting between the siding and the walls of the trailer, near the leading edge of the sides of the trailer. On my return trip home, the air blew the siding out like a balloon and popped the siding out from behind the edge molding. What I need to find out is where the air is coming in. I am unable to determine this and I would like to repair this myself. Any ideas? Tom, (La Quinta, CA) 

Tom, if air is getting behind the siding, then water can also. I’d recommend a thorough inspection be performed. The first thing I would suggest you do is completely remove the front edge molding on the affected side of the trailer. After the molding is removed carefully clean off all the old putty and sealant and set the molding aside. Next clean all putty and sealant remnants still on the corner of the trailer. Access the roof of the trailer and thoroughly inspect the front roof transition molding for gaps in the sealant, especially close to the front corners. Do the same with any roof fixtures nearby such as roof or sewer vents, TV antenna, etc. Be sure to clean and reseal any cracks in the sealant. 

Back down on the ground, with the edge molding removed, carefully pry open the sidewall as much as possible and use a flashlight to inspect the framework behind (this is assuming you have soft side walls and stick construction). Reach your hand in and feel the insulation. Hopefully it is dry inside. If the insulation is slightly damp it can probably be dried by propping open the gap between the siding and framework and directing a portable heater into the opening. Leave it on for at least 24 hours or until it is totally dry. Reassemble the exterior wall once the innards are dry. 

A staple gun was probably used to secure the edges of the siding to the framework during manufacture but you can use small tacks or staples. Just be liberal with them. The more you use to secure the siding, especially on that leading edge, the less chance of it pulling loose again. Apply Eternabond DoubleStick tape along the inside edge of the molding and reinstall each molding piece. Be sure not to tighten the screws too tight or they will strip. Use a larger size screw or install additional screws in that area if some are indeed stripped already. Make absolutely sure that the molding properly covers and overlaps the bitter edge of sidewall material. 

It is possible that the sidewall skin is cut too short in some areas and that the molding doesn’t completely cover it. This could also be the cause of the air leak. If may be necessary to “cheat” the molding further inboard so that it totally covers the edge of the siding all the way around. If the siding has dips and valleys by virtue of its design, apply more than one layer of Eternabond tape. You’ll want all the gaps completely filled in. Using a utility knife, simply trim the excess and do another thorough inspection for gaps in the sealant.

Is It Pre-wired for RV Generator?

We are considering adding a generator to our coach. We want a generator and have heard our model is prewired for one, however we are not sure. How do we tell, and what type should we get? Steven, (Berwick, PA) 

I'm assuming you have an older motorhome Steven. So, to know that a coach is pre-wired for a future generator installation, look inside the proposed generator compartment. It should be equipped with a louvered door to allow for the ventilation requirements of the power plant. Secondly, there will be an electrical box mounted somewhere inside that compartment. Called the generator “make up” box or “J” box, it will contain conductors that run from the generator compartment to the main panelboard distribution box, (breaker box), somewhere inside the RV. Or, it may be routed to a dedicated 30-amp receptacle located near the shoreline cord entrance, such as shown in the photo here.

At the main breaker panel, you may also find a separate circuit breaker labeled for the generator or at least space for one. Some coaches also come from the factory with an automatic transfer switch already installed. This device will automatically switch the source of AC voltage from the shoreline cord to the generator after it is started. If there is no automatic transfer switch on-board and there is a 30-amp receptacle at or near the shoreline cord, then you must plug the shoreline cord into the generator receptacle in order to power the coach. There may also be a plugged fuel line already run into that compartment as well. Plus the compartment will be metal-enclosed.

And don’t forget, you can always contact the coach manufacturer (assuming they are still around!). By providing them the model and VIN number of your motorhome, they should be able to tell you how that particular coach was outfitted as it left the factory.

As far as generator brand, there are quite a few nice models currently available. I’d suggest seeking out information for suppliers having a proven RV track record for starters, but I certainly wouldn’t rule out any of the newcomers to the RV market. I’d probably have to start from scratch and download info from any and everyone who currently makes an RV generator, making sure it is indeed approved for RV use. There are quite a few options today. Do your homework and compare size, output rating, cost, fuel efficiency, etc., prior to making the decision.

Don’t forget, you’ll have to first mathematically “size” the RV to determine how much power you’ll actually need. In other words, based on the 120-volt devices in your rig, how much wattage will you actually require? The answer to this question will determine what “size” generator you should consider. Once you’ve done the math, add another 20-30% for a safety buffer; keeping in mind, you’ll also be plugging in devices like coffee makers, curling irons, etc., in addition to the built-in or “hard-wired” AC loads associated with your particular motorhome. The bottom line; always have more output capacity available than you’ll typically need at any given time.

RV Damage Due to Tire Failure

I have a Class B motor home and was driving down the highway when the rubber from the rear outside tire flew off and took out the insulation and cabinet bottom, water lines and a host of other things. As the stuffing flew out, it caught something underneath on the other side and knocked out the floor under my bathroom cabinet. Is this common or did I just have a bit of bad luck. I would really appreciate knowing while I wait to see what the insurance company has to say. Cory, (Omaha, NE) 

Cory, I would have to say that you indeed had a case of bad luck with that tire separation. The damage caused by a separating tire can either be minimal or much worse in many cases. Road speed, type of coach construction, how large the pieces were, etc., all plays a part. I’d hazard that no two instances will be identical. I would, however, caution you to be sure and let the insurance company know that every system, propane, battery, 120-volt AC, fresh water plumbing, waste water plumbing, etc., will need to be fully tested after all the physical construction repairs are completed. It’s not simply a matter of rebuilding the structural components. There may be unseen damage that can only be revealed through a series of tests on each of the systems.

Plus it's important to fully analyze why that tire failed in the first place! Have a professional service technician or tire safety expert conduct a thorough investigation to determine the cause. Overloading, improper air pressure, faulty tire or other failed equipment may have been the cause and a close inspection is a mandate against further complications later on.

This might be a good time to remind everyone about the great work performed by the RV Safety & Education Foundation (RVSEF). My good friend, Walter Cannon, heads that organization and is the leading expert in tires, weights and safety for all RVs. Be sure to check out the information posted here.