Hello,
I installed a new water heater 3yrs ago,replaced upper element 1yr ago.
Had 6 months problem free after installing element.
One day water started slow dripping from the relief valve on the side. Thinking the valve might be at fault I replaced it with a new one- same problem still exists.
I "worked" the valve to make sure it's seated OK, and the only other thing I found here was that it's possible the water inside is turning to steam, causing the pressure build up/ release?
The temp control is set @ 115degrees, but I measured the tap @ 132. Bad thermostat?
Even at 132 is that hot enough to cause the steam-overflow situation?
It isn't possible to have too much pressure in my lines (county water) that could cause this, is it?

I doubt this is relevant, but I'll add that my kitchen faucet started dripping hot around the same time- I replaced the cartridge/rings and the drip won't go away- it's like it's haunted :eek:

Any help for me? Thanks!

The 115 degrees is much too low for the temp on the T & P valve. It should be much hotter. Also it is set at the factory and after three years it could have problems causing it to start dripping. If you are getting 132 degree water from the heater the 115 degree T & P valve should be leaking water all the time because that is what they are designed to do is let water off it the temp gets hotter than the setting. If you think the theromstat is faulty and is not turning off the power you can open a hot water faucet and if you get steam out of it you should turn off the breaker to the heater and replace the thermostat.

Hello,
I installed a new water heater 3yrs ago,replaced upper element 1yr ago.
had 6 months problem free after installing element.
One day water started slow dripping from the relief valve on the side. Thinking the valve might be at fault I replaced it with a new one- same problem still exists.
I "worked" the valve to make sure it's seated ok, and the only other thing I found here was that it's possible the water inside is turning to steam, causing the pressure build up/ release?
the temp control is set @ 115degrees, but I measured the tap @ 132. Bad thermostat?
Even at 132 is that hot enough to cause the steam-overflow situation?
It isn't possible to have too much pressure in my lines (county water) that could cause this, is it?

I doubt this is relevant, but I'll add that my kitchen faucet started dripping hot around the same time- I replaced the cartridge/rings and the drip won't go away- it's like it's haunted :eek:

Any help for me? Thanks!


Let me take the mystery out of it for you. I started to get a lot of calls exactly like yours when the code department began requiring check valves and backflow preventers on all water services.
Let me explain what's happening and how to prevent it.
As water heats it expands. The extra pressure could always be absorbed by the water backing out in the water service and into the street main.
Along came check valves and backflow preventers and closed off the path the pressure took to relive itself. Having no other place to go it bult up in the heater to the point where it tripped the relief valve. The extra pressure might even be the cause of your drip.
To repair this problem you have to give the extra pressure someplace to expand to. You will have to install a expansion tank on your cold water heater supply, (see image) This is not as difficult job but will require you to have some plumbing skills and soldering tools and experience. More questions? I'm as close as a click, Good luck, Tom

If you, or the county, have added the now common backflow preventer, but not an expansion tank, Tom is exactly right. Do what he says.

I've got plenty to go on now, thanks so much!

I love you guys- I got the help I needed in less than an hour! WOW!

-Brian