Water heater pressure release valve

I removed ours 2 years ago and soaked it in vinegar for a couple of days. Installed it and did the air chamber deal and not leaking yet.
chevman

no one mentioned that these valves are temperature and pressure valves your heater could be getting a little too hot

kemer wrote:
2002 Montana. How easy/difficult is it to replace a pressure release valve on the water heater? Mine has a slow drip that probably will just get worse as time goes on. THANKS

Are you sure you have an air trap at the top of the tank. If there is no air trapped at the top then the expanding water will cause the pressure relief to drip and appear to be faulty.

To restore an air trap at the top of the tank:
1. Turn off water pressure/source.
2. Open a hot water tap.
3. Open the pressure relief valve and allow water to drain to that level.
4. Resume normal operation.

rhagfo wrote:
Pressure relief valve should not drip, the air space has nothing to do with it.

The 'air space' has a lot to do with it

Water can not be compressed......air can
Water expands when heated and as it expands it needs an air pocket that will compress otherwise pressure will increase . When pressure increases due to expansion of that heated water the PRV will weep.

Both Suburban and Atwood explain this.
Both mfg. design an air pocket into WH tanks using dip tubes



And as a commercial boiler operator I can testify to the expansion & subsequent pressure increase when heating water.

I would flip it off and on a couple of times... Mine will drip from time to time and that is what I can do to stop the the drip...

Roy Ken

Pressure relief valve should not drip, the air space has nothing to do with it.

Read the Manual. Your RV has a closed water system and the water heater relief valve is what keeps the pressure in check. It is normal for it to drip. Change it if you want, but I can assure you the new one will drip as well.

Maintaining the airspace in the water heater tank helps the dripping somewhat.

Difficulty is relative......
Biggest issue is adequate room/clearance to properly get a wrench on it.
Sometimes it is just easier to remove exhaust vent if in the way.

And a dripping relief valve doesn't always mean that valve needs replacement.

Deposits can build up on valve seat causing it to not fully close.
Blowing valve out (opening valve and letting it snap close a couple of times WITH water supply turn on) will clear seat of debris

Also.if dripping is during heating cycle then 'air pocket' has been lost and pressure has increased enough to cause relief valve to 'weep'.
Air Pocket
Turn off water supply
Open closest faucet to relieve pressure (hot side)
Open PRV via lever.....let snap close when water stops flowing out
Turn on water supply
Close faucet

It's probably just threaded in. Drain the tank, use a wrench to remove it, buy another one. Try a local hardware store or one of the big box stores like Lowes. Take the old one with you and show it to the guy working there.

Get a roll of teflon tape and tape the threads on the new one, get the guy at the hardware store show you how if you haven't done it before. Screw the new one in and tighten with a wrench.

If it is just leaking at the threads the old one may just need to be pulled out, taped with teflon tape and put back in. If it's leaking on the valve body then replace it.

You may want to replace the anode at the same time and possibly flush the tank out.

This may be the best type of Teflon to use.