American Coach: Weeping new dometic water heater

[mdmiles817]

Hello guys. I have a 2000 Eagle 40EVS. I just updated my water heater. It is a 10 gallon electric/propane heater. Before I replaced my old one it has started weeping only when I have the water pump on. I had replaced the t&p valve with no resolve. New heater. Same issue. I have tried numerous times to reset the air pocket with no help. I also replaced the pressure regulator coming out of the hot side of the tank.

Thanks for your help. I gotta go bluegrassing very soon and I need hot water. Lol.

[cavie]

Originally Posted by mdmiles817

Hello guys. I have a 2000 Eagle 40EVS. I just updated my water heater. It is a 10 gallon electric/propane heater. Before I replaced my old one it has started weeping only when I have the water pump on. I had replaced the t&p valve with no resolve. New heater. Same issue. I have tried numerous times to reset the air pocket with no help. I also replaced the pressure regulator coming out of the hot side of the tank.

Thanks for your help. I gotta go bluegrassing very soon and I need hot water. Lol.

I was told by an old salt RV tech 5 years ago. "let it weep".

[camper8251]

Where is it weeping from?

[Skip426]

If your drip ( weep ) is from the temp /pressure relief valve , and external from the RV ( runs outside ) it's not unusual .

Opening the valve to vent air from the tank is the problem , leave the valve closed and vent the air from the tank through the outside shower and internal tap sets ; yes it's messy but the T/P valve seldom re-seats properly .

[mdmiles817]

It’s more than a drip. It’s literally pouring out. I haven’t even hooked electricity back to it yet. I just turned in the water pump to check for leaks and once the tank is full it just starts loosing water and the pump just keeps running.

Thanks again

[Spdracr39]

Since it is new why not call Dometic and see what they say? If you paid to have it installed make them figure it out.

[KF5UMC]

I understand you have a new heater but for future reference...with a leaking pressure blow out valve, suspect your thermistor temp sensor mounted on the tank is bad. Does the problem occur on gas and electric? There are two sensors mounted on the water tank. One for Electric power and One for LP Gas.

If the sensor is not opening at a predetermine temp, your bypass valve will open due to excessive high temp.


If it is weeping, locate the sensors unplug the two wires and measure the resistance. Should be OPEN (infinite resistance) when a set temp is reached.


Good luck
John

[Old-Biscuit]

Originally Posted by KF5UMC

I understand you have a new heater but for future reference...with a leaking pressure blow out valve, suspect your thermistor temp sensor mounted on the tank is bad. Does the problem occur on gas and electric? There are two sensors mounted on the water tank. One for Electric power and One for LP Gas.

If the sensor is not opening at a predetermine temp, your bypass valve will open due to excessive high temp.


If it is weeping, locate the sensors unplug the two wires and measure the resistance. Should be OPEN (infinite resistance) when a set temp is reached.


Good luck
John

Regardless of Brand....Water Heaters have SET of t-stats.
A Normal Temp T-stat that controls heating cycles (Opens at 140*F for Atwood---Closes for reheat at 110*F)
Then there is a Hi temp T-stat (ECO --Energy Cut Off for Atwood. TRIPS/Shuts down DC/Locks Out circuit board so NO more heating can occur until Reset by OWNER) It trips at 180*F


T&P Relief Valve is 3rd safety device to handle extreme overheating.....Normal/ECO t-stat FAIL and heating continues.
T&P POPS open at 210*F/150psi. Will begin 'weeping' at 125psi


T&P pouring water out without any heating and water pump running......
Either that T&P has FAILED OR is staying open because 'lever' is holding it open.
Release the lever and let the T&P SNAP Close.


If FAILED..........replace it.
Standard 3/4" NPT with short probe...any hardware store (same as residential ones)




Air Pocket at top of tank will occur during normal fill of WH tank....Bleed air out of system via FAUCETS NOT T&P


TO re-establish air pocket...
Turn water supply off/open faucet to releave pressure (Hotside)---LEAVE OPEN
Open T&P via lever allowing water to run out until it stops---then release lever/SNAP T&P Closed
Turn water supply on.....close faucet when air is bleed out


Loss of air [pocket can cause T&P to 'weep' DURING heating cycle...water swellls when heated. No air pocket----internal pressure will increase (air can be compressed/water will NOT)

[mdmiles817]

Once again thank you. It only does this when I use my pump. When I hook up to city water it doesn’t happen. Also, it does this while not being powered on. In other words no electric and no propane.

Thanks

[Old-Biscuit]

Originally Posted by mdmiles817

Once again thank you. It only does this when I use my pump. When I hook up to city water it doesn’t happen. Also, it does this while not being powered on. In other words no electric and no propane.

Thanks

If it (T&P Relief Valve) LEAKS when using pump it should do same when connected to City Water

What pump do you have..what is it's discharge pressure??

Pump/City Water fed SAME plumbing system and typically city water/pump pressures are close to being same.





You stated something about 'changing pressure regulator on Hot Out'


Pressure Regulators are used on City Water inlet
Check Valve on WH Tank Hot Out
2 different devices...different functions

[KF5UMC]

Understand its new but is there corrosion around the stem / valve seat on the T&P Relief Valve? Relase the pressure and Open the valve and inspect the valve and check for sticky action. Try tapping on the head of the valve stem to seal it...