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econdave 08-22-2008 02:32 PM

water heater PRV valve leaking
i just installed a new hot water heater. The Pressure reliefe valve is leaking on top of the tank. How can I stop it. I have tried tightning it but I am affraid to go any tighter. Can I unscrew it, teflon tape it and put screw it back in?

bob22 08-22-2008 03:46 PM

Yes, it should be installed with either pipe dope or teflon tape. The discharge piping for that valve should face downwards towards the floor (about 6" above floor) and not left without such a tube to prevent people from getting burnt if it releases. You'll obviously have to shut off water, drain water below level of the PRV, and do the repair. Did it come with one pre-installed or did you have to supply your own?

econdave 08-22-2008 03:51 PM

thanks for reply, it came pre-installed. The valve is on top of tank, so do I have to drain water? Can I just shut off water supply, back it out and teflon tape and dope it?

bob22 08-22-2008 03:56 PM

Remember that the pipes above your water heater all have water in them and when you unscrew that PRV, all of that water will want to "fall" out of them. I don't know if you want your new heater to get all wet or the area it is in but you could if you want (I wouldn't if it were electric). Just drain off enough to get it below the level of the PRV (open spigots in fixtures above to get the water to come out easily).

econdave 08-22-2008 04:17 PM

O.K. so shut off water, run faucets upstairs to relieve pressure, unscrew PRV teflon and dope it? thanks again.

bob22 08-22-2008 04:57 PM

Yep,that should do it.
You shouldn't need to use both teflon and dope. Usually 3 wraps of teflon is all that is needed or a generous application of dope. Nothing bad will happen if you use both however.
Make sure you turn off heater (electric at panel) or gas, turn pilot to vacation/off. You don't want the heater to try to run if the elements (electric heater) are exposed as they will burn up in air without the water to cool them.

econdave 08-22-2008 05:54 PM

o.k. will do. Will keep you posted on outcome. Thank you for your help in this matter.

bob22 08-22-2008 05:58 PM

Glad to help.

Nestor_Kelebay 08-23-2008 12:58 AM


Where, exactly, is the water leaking from?

If water is leaking out where the PRV threads into the top of the tank, you might want to contact the manufacturer before you do anything. It may be a cracked tank that might be covered under warrenty.

If you change the PRV on a tank that's still under warrenty, you might have difficulty convincing them that the tank was leaking before you replaced the PRV. And, then you have a cracked tank with no warrenty.

Also, look on the cold water inlet and hot water outlets on the piping to that tank. There will normally be shut off valves on both the inlet and outlet lines to the tank because water heaters periodically need to be replaced. You might want to simply close those valves instead of draining the water down to an elevation below the PRV.

Phone the manufacturer of the tank to find out if you can get a new tank even if taping or doping the PRV threads doesn't solve the problem, and confirm that the PRV has a 3/4 (?) pipe thread on it's bottom. Then, after buying a plastic 3/4 inch plug from your local home center:
a) shut the isolating valves
b) open the heater's drain valve for a second or two to release the static pressure inside the PRV. You should get an initial strong flow of water that will quickly peter out to nothing. Close the drain valve.
c) screw out the old PRV and immediately thread in the plastic plug
d) tape or apply pipe dope to the PRV's threads
e) unscrew the plastic plug and screw in the PRV. Tighten it.
f) open the isolating valves and see if it still leaks
g) if not, attach the piping that carries any hot water discharge from the PRV to the floor.

Even if there is no shut off valve on the hot water outlet of the heater, unscrewing the PRV will cause very little water to fall out of the hot water supply piping because that would result in a vaccuum being created in the hot water supply piping. That is, for water to come out, something must go in to replace it. Otherwise atmospheric pressure will keep the water inside the tank.

Please contact the heater manufacturer first. You might end up shooting yourself in the foot if you don't.

econdave 08-23-2008 06:10 AM

I called the company "GE" and they are sending a new PRV. I should recieve it today, they over nighted it.

econdave 08-24-2008 06:38 AM

now I am not sure where the water is coming from. I know the water supply pipes are not, I think the water is coming from the cold water nipple going in to the top of the tank. Can I back that out and teflon tape it and screw it back in without draining tank?

buletbob 08-24-2008 06:48 AM

is there any unions on the pipes leading to the top of the heater? turn the shut off values off on both hot and cold. drain the heater just a bit to lower the water level in the tank. unscrew the union and and do what needs to be done.

econdave 08-24-2008 06:58 AM

yes, i installed unions. I will shut water and disconnect union on cold side and take nipple out and tape it. Thanks, will let you know how i make out.

econdave 08-24-2008 09:47 AM

O.K. I re-installed cold water nipple back in to tank. Shut off water at the street, drained lines and pumped my expansion tank back up to 90 PSI now the waiting game to see if a puddle appears on top of tank. All plumbing pipes are dry, no leaks from them. So the only place water can come from is hot/cold nipples or Pressure relief valve in which I gently stuffed paper towel in to see if it gets wet.

buletbob 08-24-2008 10:00 AM

you should have a 3/4" threaded coupling installed at the prv and then a small 3/4 pipe going into a 3/4 union and another small piece of pipe connected to a 3/4" 90 and the running down along side of the heater about 6' off the floor. the union after the PVR is in case you must change the PVR at a latter date. instead of UN sweating everything. BOB

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