Water Heater Leaking

[ericmac450]

Hi All,

Need some help identifying my issue and help walking back from the ledge .

2021 Thor Daybreak 30db Class C
Dometic GC6AA-10E (6 gallon tanked water heater)

On our last trip we had water leaking from the back of our water heater and across the floor of the RV. (Our water heater is in the slide and a pain in the butt to get to.) I shut off the cold water intake into the water heater and we went the rest of the trip without hot water and we had no more leaks.


Today I went and tested it. When I first turned everything on (gas and electric plus water pump) I ran each faucet and made sure there was no leaks.
When the water heater is cold (low pressure) there is no leaks.

Perplexed, I sat there for a couple minutes and let the water heater work. After 5-10 minutes, I could hear a hissing sound and finally started to see some water coming out.

Water starting to puddle/leak.


Once again I checked all the fittings and could not find any water coming out. I went outside and there are some drips coming out of the high pressure fitting, but not near enough to flood the RV like what was starting to happen again.
All fittings seem tight and no leaks


Water dripping out of the high pressure fitting


Water on the outside


What else can I check/do? Is there something I'm missing to check? Should I try to just replace the high pressure fitting first? Or could my water heater be cracked?

[Pete'sMH]

Mine was leaking from the back and it turned out that the electric heating element was not tight. I had to remove the whole water heater to fix it. It was not really difficult.

[Grumpy Grampa]

Pressure release valve, releases water when under pressure. Replace

[ericmac450]

Originally Posted by Grumpy Grampa

Pressure release valve, releases water when under pressure. Replace

After your post I went and opened and reseated the valve, then tested again. I didn't see any water this time.

I've also read that the water heater has an air gap at the top that could have gotten filled? I was going to try and follow the Atwood instructions on that while I wait on the replacement part to come in. Anyone tried that?

[Beau388]

Interesting plumbing. I thought PEX piping was universal these days. I don't think I have a screw clamp a anywhere. They are all pinch type even on the city water inlet. The 1/4 turn valves are metal, but the fittings are plastic.

[ericmac450]

Originally Posted by Beau388

Interesting plumbing. I thought PEX piping was universal these days. I don't think I have a screw clamp a anywhere. They are all pinch type even on the city water inlet. The 1/4 turn valves are metal, but the fittings are plastic.

I had a water line burst coming out of the back of the water heater over the winter. Everytime I have to get under there and look at that mess it makes me want to scream! I feel like there are more durable solutions out there.

[blw2]

If it's leaking from your TPRV (relief valve)

I found mine doing that some years ago. I found that there is normally a pocket of air inside the tank. Over tim, that pocket of air can go away...absorbed into the water i suppose.

Once that happens there is no cushion in the tank to soak up the expansion from heating. Liquid is not compressible but air or vapor is compressible. So when the water heats, it expands. But when the faucets are all shut, there is no place for the expansion to go.

The fix.
with the heater cooled down
Shut off your water and crack open a faucet lower than your water heater tank. My outdoor shower is perfect for this.
next, crack open the TPRV and let it vent. Air will go into the tank and the water will drain form your low point drain (my shower in this case)
You don't have to drain it empty but you'd might as well to flush it out....
Next, close the TPRV and turn the water back on.

Water will refill the tank, but a pocket of air will be trapped inside....

edit: disregard... i didn't read the whole thread carefully enough. Ericmac450 nailed it, with graphics no less! Solved your own problem I hope. How did it work out?

[PreCambrian]

Originally Posted by ericmac450

After your post I went and opened and reseated the valve, then tested again. I didn't see any water this time.

I've also read that the water heater has an air gap at the top that could have gotten filled? I was going to try and follow the Atwood instructions on that while I wait on the replacement part to come in. Anyone tried that?

Leaking from the Temperature/Pressure Relief valve is a common problem. Lifting and reseating will often solve the problem. It also establishes the air pocket at the top in case the water heater has been overfilled or has lost the air pocket. Just lift the lever, let the water run out until it stops, then reseat. I have also had water leak from my plastic drain plug so sometimes it needs tightening.

[ericmac450]

I reset the air pocket today. I tested it and didn’t see any more leaking. I went ahead and purchased a new pressure relief so if it leaks on me next week while camping I can swap it out.

[ericmac450]

Thanks for the direction, I was convinced when it happened that I was going to have to buy a new heater! Y’all’s check is in the mail!