Water heater cools off too fast.

[Rickf1985]

My water heater will come on about every three hours even when no hot water is used. This is on a 70 degree day. I am at work so I don't have the specs on the heater in front of me but I know the heater in my slide in truck camper is almost identical and will go all day without running. I figure that since there was a leak in the roof above this heater that the insulation may have gone flat. Have any of you had this problem and fixed it? I can get the heater specs this evening if needed.

Rick

[DaveVA78Chieftain]

Sounds like a insulation problem.  Use a meat thermometer in a cup of hot water to measure water temp at shut down.  Mine shuts off at 130.

Dave

[ClydesdaleKevin]

My old Atwood didn't have any insulation at all...mice had carried it all away.  I used a small electric water heater fiberglass insulation sheet and cardboard taped together and made a new insulation shroud.  Now we have on demand hot water, but that was how I insulated the old one.

Kev

[Rickf1985]

Are you talking about the fiberglass insulation add on you buy at the store to wrap around the water heater? (For a regular house type heater)

[ClydesdaleKevin]

Yep.  Wrapped it tight around the heater tank, taped it down with Gorilla tape, then made a cardboard cover for it, also taped down with Gorilla tape.  Held up for years before I switch over to the tankless heater.

Kev

[Rickf1985]

OK, Found my water heater today and actually I can see it quite well. It still has the original cardboard and the insulation I am assuming is good since nothing has been disturbed. Why would it be calling for heat every four to five hours when not in use? I have one theory. The heat exchanger that uses the engine heat while driving is working in reverse when not driving and using the water heater to heat the water in the engine heater lines? I guess I could get some old style Ford heater control valves which are cable controlled and put them in the lines under the heater and put the other end of the cable in the closet above the water heater. When not driving just pull the cables. That is the only place I can figure the heat is going. I am going to fill it up and fire it up now that I have access and see what gets hot I guess. That is probably the easiest low tech way of checking. Dang, I answered my own question! I AM good!

[Froggy1936]

Rick Yes you are losing some heat to the veh cooling syestem , But realize that it is only a 6 gallon tank and 4-5 hrs is quite a wile , The 6 gallons will cool off a lot faster than a 40 gallon house  hot water heater . I do not think you have any problems worth trying to extend hot times ! A better solution is to install a hot rod (electric water heater element) Since installing mine i have never had to use the propane again Frank

[Rickf1985]

Frank, I have the very same heater in my slide in which is an 88 and it stays hot all day and night. Just the heat of the pilot will maintain the temp. I am losing heat somewhere, I have it heating up now and after it stabilizes and sits for a while I am going to see what is hot outside of the tank. I have two rubber hoses from the vehicle cooling system right in the coach at the heater so adding remote valves would be easy. Those hoses are 25 years old and NEED to be changed anyway. Same with the ones in the back at the aux heater so I will be draining that whole run and doing all the rubber lines at once and adding valves to both heaters.

[Rickf1985]

Well it looks (feels) like my insulation is shot. I am going to have to peel the cardboard wrappe off and see if critters have absconded with it but the top of the unit was hot so I am losing a lot of heat there and some on one side. Surpisingly none through the heat exchanger lines.

[pvoth1111]

That's a undocumented feature....keeps the engine warm for proper......uh somthin i??

[DaveVA78Chieftain]

Part of the design to keep the burner nozzle clear of spider webs.   

[Rickf1985]

The spiders moved over to the fridge burner.