ris wrote:We plan to spend 3 to 4 months a year in our cargo conversion. Need info on water heaters from those that use them a lot. Do we get a tankless eco temp or a surburban tankless (over $500), a 6 gallon tank water heater. We will be using only propane. Need some help with info. Seems like all of them have a lot of negative reviews. The water heater will be in our utility room at the back of the trailer. We can open the doors to the utility room to vent. Our build is under 2017 18 X 8.5 by ris. We are used to boat showers. Get wet, turn off water, soap up, turn on water to rinse. About 3 gallons per person. Thanks for the help.
Richard
Hello Richard,
Funny you should mention boat showers. About 10 yrs back I bought a Camper and it had everything but a shower that I needed. I like being off grid camping and so I looked around and found on Craigslist a heat exchange 6 gal water heater from a boat for about for $75.00. It has a heat exchanger you connect to your engine cooling system. I can run my truck for 15 minutes and have 6 gals of 180deg hot water (The same temp as my vehicle thermostat). I wrapped the tank in fiberglass insulation and it holds the heat for about 24 hours and is still warm enough, in mild temperatures, to take about one comfortable shower, using the Boat shower method you mention above.
As it had a port to install an electric heating element I decided it would be nice to have and electric option. So I found at camper supply stores you can purchase an electric element kit from Dometic I believe, that runs on 110-220 volts. But they were to expensive for me and I am cheap! So I started to look else where. Unfortunately the commercially available heating elements would draw more current that my electrical system was designed for and most provided way more heat than I needed. They started about 1400 watts and go up. The 6 Gal tank does not need that much energy. But the good news they were very cheap! Yahoo... Not wanting to overload my electrical I still needed a different option. I was struck by a stroke of genius!! The elements come in 110 Volt or 220 Volt. Why not use a 220 volt element on 110 volts and by selecting a 1400 watt element I should draw 750 watts. This was within the capability of my system and still allowed me to run the rest of my electrical in the camper.
So I picked one up at Lowes and installed it with a popoff valve for safety, added a high/low thermostat that straps on the tank and added a clock/timer so that the heater only turns on a couple times a day and runs just long enough to heat the water.
To my surprise I stuck a clamp on amp meter to the element and almost had to pick myself off the floor - no I wasn't electrically shocked - The element draws 3 amps or 360 watts and is more than enough energy to heat the water in a reasonable amount of time. I can even run it on my 750 watt inverter off of my house battery. I have tried it and it works although it does take a toll on the 12v battery.
Since then I have used it for a month at a time over several years and it is still doing an awesome job.
It occurred to me that the elements rarely open up they increase in resistance and put out less energy so people replace them you might be able to find one in an old electric water heater that stopped working that would work for the small 6 gal tank for free? Who knows? Good luck with your project.