Is there a plumber in the house?

shootist16

shootist16

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The pop-off valve aka T&P valve on my gas hot water heater has been leaking. I replaced it, but it still leaked (though not as bad). Yesterday I replaced the water pressure regulator, but the pop-off valve still leaks. Any ideas on what the problem could be?
 
A guy I worked with had a similar problem with his T&P valve leaking. When hot water was being used and the water heater was on, his T&P valve would leak when the water was turned off. Almost a water hammer type situation. He ended up putting some sort of expansion tank in the plumbing next to the water heater. It looked to be about 3 or 4 gallons in size and it had an air bladder that would absorb some of the "shock" when the water was turned off. His T&P valve stopped leaking after it was added.

Hope this made some sense,

Bruceter
 
Bruceter said:
A guy I worked with had a similar problem with his T&P valve leaking. When hot water was being used and the water heater was on, his T&P valve would leak when the water was turned off. Almost a water hammer type situation. He ended up putting some sort of expansion tank in the plumbing next to the water heater. It looked to be about 3 or 4 gallons in size and it had an air bladder that would absorb some of the "shock" when the water was turned off. His T&P valve stopped leaking after it was added.

Hope this made some sense,

Bruceter
Click to expand...

I'll look into that.
 
If you have a check valve on the water inlet to prevent backflow you have to have some expansion volume somewhere. A simple expansion tank as mentioned should take care of the problem. You may have to replace the T&P valve again, though. In my experience, once they start leaking they never stop.
 
How is the temperature on your water heater? How old is your heater? Are you on a well? Do you have a water softener? Gas, or electric? Not only will pressure cause it to open, but excessive temperature will do the same.
 
Temp is on the next to lowest setting, no well, gas, i think it is about 12 years old.
 
yablanowitz said:
You may have to replace the T&P valve again, though. In my experience, once they start leaking they never stop.
Click to expand...

+1 on this. Though the manufacturers recommend you test these valves every so often, a couple guys I know swear that once you crack one, they leak forever.
 
If the lines are galvanized and the house is over 60 yrs its possible the sediment from the galvanized lines has settled in the hot water hank. I've seen were there was so much build up that about 1/3 of the tank was filled with sediment and thus reducing the capacity of the tank and causing the relief valve to open. You can try and purge out the tank to see if that helps. If the lines are copper than disreguard.
 
Dennis,

With the age of your heater I'd guess it has lime/calcium deposits on the temperature probe causing the probe to be insulated from the actual water temperature. This causes overheating and opening the valve due to temperature. JMHO
 
lureman said:
Dennis,

With the age of your heater I'd guess it has lime/calcium deposits on the temperature probe causing the probe to be insulated from the actual water temperature. This causes overheating and opening the valve due to temperature. JMHO
Click to expand...

It is possible, and I have seen it happen. On the other hand, my water heater is thirty years old and I have very hard water, but mine is still working fine. I can say that because I have a spare standing by in case Murphy takes offense . ;) :D
 
How much water is leaking and is it continuous or is it intermittent? If it's continuous I'd say that you have an overheating water heater, I seriously doubt it's over pressure, the valve tends to blow out then with some serious water flow. If it's intermittent I would expect it to be a water hammer related issue, which will require an expansion tank or at minimum an expansion T. Expansion tanks are a good idea to reduce pulsing on pipes and heaters, in the house my family is renting hammering is so bad on the cold water line sometimes the pipes rattle a few walls.
 
Plumber? Anyone need a plumber?.....
 

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