When buying an RV it is important to get it inspected and thoroughly checked out. This is particularly true on a used rig. We had our RV inspected and we thought we had been over it top to bottom, but in the course of early ownership some things came to light. A few we missed and some only revealed themselves later on.
One of the problems to manifest itself after purchase was that the hot water heater didn’t work on AC shore power, only on propane. Ours has two sets of switches inside the RV for the two systems. One turns on the propane burner assembly, and one switches between three high load appliances: the water heater, microwave, and washer/dryer. That three-way choice is necessitated by the limits of our 30 amp power system.
Our Atwood water heater is a combo propane/electric unit, which is an upgrade compared to propane only. When parked at a campground with essentially limitless electrical power, a combo unit like ours can be left on in electric mode so hot water is always available, switching it off only from time to time to run the microwave or washer/dryer. We leave the water heater turned on electric overnight so that it ready for hot showers first thing in the morning. Though a propane only unit can be left running all the time, it will quickly burn through the limited supply of gas keeping water hot while you’re not using it. It is typically only turned on for expected uses which of course means waiting for hot water in the morning, or to wash dishes. The trade off is that the propane burner will heat the water much quicker than the electric element will.
As we started our journey we quickly found that the water heater electric switch didn’t seem to do much. At first, we thought the electric element was just really weak compared to the propane burner, but it became clear it wasn’t doing anything at all and so got added to the “pending repairs” list. I started doing some reading on RV water heaters and troubleshooting their problems. The electrical side is fortunately simpler than the workings of the propane side. While the propane side has gas valves, burner tubes, flame sensors, thermostats, and a small circuit board, the electric side only has the element and thermostat and switch. And all three of those only require a multi-meter to check.
RV water heaters are famous for being difficult to work on. They are often located where only some of their components are inaccessible and frequently the whole unit must be removed to replace simple parts. Ours is a bit of a mixed bag on this. Atwood puts the electric heater element and its controls on the backside of the unit which usually means pulling the whole thing out of the wall to test and replace them. Our Fleetwood Bounder luckily has an access panel located under the RV that allows you to reach most of the rear of the heater. Unfortunately, it seems it was designed to allow access only for making a few connections during manufacturing, not servicing the unit. If anything, other than the element needed to be replaced the whole water heater would probably need to be pulled out of the RV.
I started by testing the electrical components of the water heater. First making sure power was going to the heater when the switch was on, then turning the power off and checking the element and thermostats for continuity. Access to our unit is possible though difficult, I could reach the heater element which is near the bottom of the tank,. The thermostats, however, are near the top, and to get to them I would need to remove more plumbing and pull the unit at least part way out to get my hands near them. When the element tested bad, I decided to gamble that it was the only problem and started planning its replacement.
Planning was necessary because I didn’t want to get part way in and discover I didn’t have a part needed to put everything back together. When we replaced the washing machine valves we also had to replace the hoses because the connections were old and cheap junk.
Besides the new element, I had a water heater element wrench, new supply lines and fittings on hand. The one part I had to run out for mid-project was a 1 ½ socket wrench to use instead of the “purpose made” wrench. Water heater element wrenches are simple overpriced tubes, about 4 inches long with a hexagonal stamped end roughly sized for a heater element, and holes punched in the end to pass a screwdriver blade through. I found that they are absolutely worthless when dealing with a tight element.
That tight element took a lot of torque to remove. The water heater element wrench fit too loosely and combined with the awkward overhead working position it just skipped off the thin hex end of the element. I needed a proper tight-fitting socket with a long handled wrench to break the element free, and even then only got it turning by lifting myself off the ground and using my weight to get it turning.
Laine and I picked up the new element and all the other parts at a Home Depot near the campground we stayed at in Vicksburg. After doing some reading, I went with a 240v element from a residential water heater. The OEM element was a 120v 1400 watt model, the residential 240v element was 3500w. When operated on the 120v circuit in our coach this element only consumes about 850 watts (Ohms Law and all that stuff…), so it will heat more slowly but consume a much smaller portion of the roughly 3600w we have available at any given time. Between showers in the morning we use the propane to reheat the water faster. Additionally, “under-clocking” the element this way should greatly extend its life. Interestingly the rubber washer that came with the new element wasn’t the right size to seal to the tank on our water heater, it was too thin; so I reused the old one and added a healthy dose of Teflon tape to stop any drips or leaks.
With the new element just tight enough and the water lines reconnected, it was finally time to test the system. Gently turning the water back on and bleeding the water heater showed no leaks anywhere, and in short order we had hot water coming from the taps, all thanks to electric power! Huzzah!
[Did you notice Mike's shirt? It reads - "Sarcasm is just one of the services I offer."]