Installing New Water Heater
Last summer I noticed a few drops of water dripping from my 1982 Sulnline 16 1/2. It was under the water heater so I went inside to look and sure enough it was wet in the water heater compartment. I removed it and found pinhole leaks on the bottom, of the aluminum tank. My first thought was to simply replace the tank but found that Atwood was out of business and the tanks were extremely hard to find. I did find one place that claimed to have one but the price was about the same as an entirely new unit.
I found an extensive article by JohnB on replacing these old Atwood heaters with a Dometic so I decided to go that route. I mean, how hard could it be to just swap one unit for another? Well, I found out it isn't so easy, at least for my case.
I found the Dometic heater on Amazon for a reasonable price (they really do sell everything). The job also requires filler side panels because the Dometic isn't as wide as the Atwood, a new door, and the electrical switch. The old gas only Atwood was the kind that's lit with a match from the outside, whereas the Dometic is lit electrically from the inside. I also got the sealing tape for around the edges, electrical wire, and a roll of tubing for the water line.
My first task was to address the floor that had rotted out under the leak. Peeling back the linoleum allowed me to dig out all the damaged floor material leaving a hole about the size of a cantaloupe above the metal sheeting underneath, but now I needed to figure out how to patch it. After some thought I got some wood pellets for a pellet stove and filled the hole. Then I poured polyester resin a little at a time letting it set before adding more until the hole was filled.
The next step was to frame the opening because the Dometic is not as wide as the Atwood. Inserting the new heater required a lot of trimming of the opening but it finally went in. Before installing however, I added additional lengths of wire to those on the heater so I could connect to 12 volts and to a switch. Next was to install the side filler panels and the door. The photo shows the installed unit.
The propane hookup was next and was a real pain. The copper propane tubing in the camper is of the hard kind that doesn't want to bend easily and when I tried to maneuver it to the new heater it collapsed and broke off and floor level. At this point I almost gave up and began thinking of selling the camper for cheap, but finally gave it another try. The pipe cannot be accessed from below due to the sheet metal underneath, so the only way was to cut out a circle of the linoleum and dig out an area around the pipe until I could cut it off cleanly and attach an adapter. Next I set off to Home Dopot for new tubing. The new is of a softer copper and bends easily by hand. At last the propane line was done.
The next task is to hook up the water lines. My old heater had multiple valves that allowed the heater to be bypassed so winterizing doesn't fill the tank with 6 gallons of antifreeze. However after many hours of lying on my side working through a small door on this job, my ribs couldn't take any more so I did not install any bypass capability. To see how it should be done read JohnB's article, and to see how I did it see the attached photo.
When it was all done with the propane turned on and the heater tank filled, I gritted my teeth and attached the wires to the switch. Nothing happened. Now I really wanted to set fire to the whole thing so I angrily turned the switch to off and to my amazement it came on. I was so careful about labeling the wires but some how I got them backward. The obvious fix of course would be to switch wires but as I was tired of working on this thing I took a marker and labeled the off to on and on to off.
So, now how can this camper be winterized without using gallons of antifreeze, one might ask. Actually quite easy as this is a very tiny camper with very little in the way of water lines. The process which was successful last winter, and I live in the northeast, is pretty simple. First shut off the pump and open all faucets. Then drain the fresh water tank, the water heater, the toilet and the shower hose, and then blow out the lines with compressed air. The lines from the heater area to the kitchen sink are the lowest in the system and are equipped with drain valves. This coming winter after doing the same, I will pump antifreeze until it just enters the heater tank (the lines are translucent) and shut it off. Then put some in the sink drains to fill the traps.
So that's it.