water heater relief valve?

[mowin]

New this spring Keystone Hornet.
Got to the CG this afternoon and turned the WH on. About 5 min before it turned off I noticed water dripping from the cover. It was coming from the relief valve. I tripped it quick to try to seat it but still dripped. It did stop within 30 seconds after WH turned off. Is this normal? It was running on gas.

[mowin]

I did what yamadooed described and the leak stopped. Thanks for all the help. Happy camping...

[hedge]

Mine was leaking too, I changed it out with a new one and the leaking stopped.

[TenOC]

YamaDooed wrote:
Turn off pump or shut off city water supply off and water heater. Then slow open relief valve and drain out relief valve to establish a air gap in the top of the water heater. Turn water pump and heater back on.
The reason it leaks is because fluids dont compress so when water is heated it expands out the relief valve. Thus the established air gap now compresses and absorbs the water expansion without escaping out the relief valve.
Actual procedure is in the water heater manual.

The procedure I use is that after I connect my hose to the city water I always turn on the hot water in the kitchen first. Since the hose is full of air, this air (and water) flows into the water heater and creates the required air pocket.

[Dog_Folks]

Might want to check the owners manual. My Atwood manual says a slight "weeping" is normal.

[WeGotLost]

our hornet did the same thing and we tried everything except check the temp. started the heater up and kept checking the temp and it kept climbing and i ran and shut it off at 208*. the tstat and eco were bad or were not making a good enough connection to shut it down and the pressure valve was doing its job.

got a new eco and tstat and have had zero issues since.

my vote would be to check the temp while its running, it shouldnt get over about 160-180ish

[rockhillmanor]

That happened to mine. I tripped it and it still leaked CG manager said to keep trying. We did and it did stop. He said everything should be ok that they sometimes do that.

The next time I used the HWH the neighbor told me the water was coming out the side of my MH like a waterfall. The side of my MH was so hot you couldn't even touch it. We opened all the hot faucets to drain the tank as fast as we could to get the boiling water out of it.

Only thing I will advise you from experience was we ultimately found out mine was doing that because the thermostat on the hot water heater was broke and letting the temp just skyrocket tripping the valve.

So I guess my advice would be to keep an eye on it. If I wasn't there when that happened I'm sure it would have started a fire.

[Old-Biscuit]

As mentioned RV water heaters have an air gap to allow for expansion of water as it heats.

Here is procedure from manual:

PRESSURE-TEMPERATURE RELIEF VALVE
Weeping or dripping of a pressure-temperature relief valve while the water heater is running DOES NOT mean it is defective. This is normal expansion of water as it is heated in the closed water system of a recreation vehicle. The water heater tank is designed with an internal air gap at the top of the tank to reduce the possibility of weeping and dripping. In time, the expanding water will absorb this air. To replace the air follow these steps:
Step 1: Turn off water heater
Step 2: Turn off incoming water supply
Step 3: Open the closest hot water faucet in the coach
Step 4: Pull handle of pressure-temperature relief valve straight out and allow water to flow until it stops.
Step 5: Allow pressure-temperature relief valve to snap shut, turn on water supply and close faucet.

[mowin]

YamaDooed wrote:
Turn off pump or shut off city water supply off and water heater. Then slow open relief valve and drain out relief valve to establish a air gap in the top of the water heater. Turn water pump and heater back on.
The reason it leaks is because fluids dont compress so when water is heated it expands out the relief valve. Thus the established air gap now compresses and absorbs the water expansion without escaping out the relief valve.
Actual procedure is in the water heater manual.

Thanks for the information. I'll try that. I'm seasonal and turn the water off every time we leave for the week, but I can see how the air gap would slowly get used up.

[YamaDooed]

Turn off pump or shut off city water supply off and water heater. Then slow open relief valve and drain out relief valve to establish a air gap in the top of the water heater. Turn water pump and heater back on.
The reason it leaks is because fluids dont compress so when water is heated it expands out the relief valve. Thus the established air gap now compresses and absorbs the water expansion without escaping out the relief valve.
Actual procedure is in the water heater manual.

[GpaVader]

Mine never leaks and I use mine to let out air while the system fills with water. Could you have too much water pressure? I use a pressure reducer on the in bound water....