Help!! Atwood water htr leaking at pressure relief valve

[doorguy]

I just did my annual maintenance on our Atwood water htr and had to open the relief valve to drain the tank, etc

Now it drips when the pump is on and pressurizes the system. I'm assuming this valve is not your typical residential water heater valve??? It looks like the threaded portion into the tank is smaller than the normal residential 3/4" valves.

Anyone have any experience replacing these? I'll attemp to attach pic of the valve. It is an Attwood Model #GCH10A-4E. This is on a WGBO, so it has the engine coolant lines hooked to the backside for heating up the water while driving.

Appreciate any help anyone can provide. The unit is 17 yrs old.

[Old-Biscuit]

Standard 1/2" threaded T&P was used by Atwood up thru 2006
*3/4" was also used

1/2" with 4" temp probe

[HarryStone]

Have you reset the airgap in the tank? Mine was leaking and it was caused by an insufficient air gap. Instructions should be in your atwood manual.

[Old-Biscuit]

Air Pocket.....formed at top of tank to control pressure increases WHEN heating water (swells)

Turn off water supply
Open nearest faucet to relieve system pressure --hotside
Open T&P...HOLD Open until water stops running out...then let it SNAP close
Turn on water supply...close faucet


13 yr old T&P....replace it

[Sam 3]

DH had to replace ours. Found one at Value Home centers. In the mobile home parts section.

[Old-Biscuit]

Originally Posted by Sam 3

DH had to replace ours. Found one at Value Home centers. In the mobile home parts section.

Hope it was one with at least a 4" temp probe so it reached down into the water
*shorter than 4" it will not be immersed in water far enough

T&P---Temperature and Pressure
Temp is sensed with the probe...pressure is sensed within the body

[akeagle]

Originally Posted by doorguy

I just did my annual maintenance on our Atwood water htr and had to open the relief valve to drain the tank, etc

Now it drips when the pump is on and pressurizes the system. I'm assuming this valve is not your typical residential water heater valve??? It looks like the threaded portion into the tank is smaller than the normal residential 3/4" valves.

Anyone have any experience replacing these? I'll attemp to attach pic of the valve. It is an Attwood Model #GCH10A-4E. This is on a WGBO, so it has the engine coolant lines hooked to the backside for heating up the water while driving.

Appreciate any help anyone can provide. The unit is 17 yrs old.Attachment 338885

When you flushed the tank, was there a lot of sediment? if so, some may have been trapped under the rubber seal of the T & P valve.

Try quickly releasing the pressure a few times with the lever on the valve. That might be enough to dislodge the debris from the seal. If it doesn't stop the leakage, you may have to replace the valve.