Water Heater problem

Couple months ago while camping with city water, I fired up the propane water heater and after it cycled, noticed water dripping underneath trailer at the front of the wheel well. Investigation finally revealed the leak was at the hot water connection area to the kitchen faucet. As others have stated, this is a pain to reach. No leaks unless the water heater is heated up. Last week, I turned propane heater on and while sitting inside, heard a lot of water running. Finally went outside and there was a large puddle of water under trailer which appears to have come from the pressure relief valve. Water was very hot, plus I turned off the water heater and shortly the valve stopped flowing. Kinda thinking the hi-limit must not be working. Any way to test this electrically? (I have DVM).

Any ideas??

Don't have any input on testing your problem, but we have always vented our hot water once or twice during every heating cycle. If we don't it will often leak from the pressure relief valve. There is enough expansion and gas creation during heating to justify a quick vent using the kitchen sink hot water valve. Have not had any issues thereafter.

[Bill]

Joe -

Although it is possible that your high-limit switch is bad, I'm thinking it is not likely. Question - does it do the same thing when heating on electricity? If yes, then you can eliminate the overheat switch as a cause.

Along the lines of MisterP's thought, it is important that the water heater be completely full of water before firing up the heat. Before turning the heater on (either electric or gas), you should run water from the kitchen hot water faucet until all bubbling and burping stops and you get a solid stream of clear water.

Why is this important? As you may know, air expands A LOT when it is heated. Water expands, too, but only a tiny bit. If you have a pocket of air at the top of the heater, and turn on the heat, then the air will expand ferociously, and the only thing that keeps the heater from exploding under this pressure is that the P/T valve opens and relieves the pressure. And you are right - turning off the burner stops the expansion, so the P/T valve closes again and the "leak" stops.

By the way, the water coming from the heater is supposed to be very hot - hotter than the water at home. So I don't see a problem there.

Let us know how the above two suggestions affect things.

Bill

To clarify one point, ours requires an occasional vent into the kitchen sink even if no air is present. We only heat with propane, and the water pressure rise will cause our relief valve to weep if I skip the venting.

Does the burner for the water heater shut off when the water gets hot? it should. You should be able to hear it when it’s lit. I’d also replace the relief valve. Whenever I had one start to leak, either home or RV, it would need to be replaced and it solved the problem

Ed

Thanks all, I always make sure I have full stream from hot faucet when I couple to city water. I had used the water heater before but the only thing I noticed was the hot water connection at kitchen sink leaked, no pressure release issue. I have not tried the electric side, but need to try it. Prior owners stated they did not use electric because it made the water too hot. Now that I think about it, that sounds a bit strange. When I checked the anode, it was almost gone and the tank had a LOT of white scale in it. Haven't had it set up since the issue and since we have ice right now, probably won't for a while. Will revisit this when it warms and test it here at home where I can watch it better.

[Bill]

Digger and Hawkeyez -

The water heater's elements, both gas and electric, are thermostatically controlled, and will shut off when the water reaches the set temperature. In both cases, the water will get very hot - much hotter than in your home water heater. The reason for this is simply that the heater has a very small capacity. In order to make that small amount last, you are expected to mix a little bit of very hot water with a lot of cold water.

Bill