Pressure relief valve had water draining from it, replace?

[clarkgriswold]

Hello,

I'm brand new to the forum here. First post and I'm requesting some advice if anyone could be kind enough.

The water sensor went off last night on my AO Smith electric hot water heater. I got down in the basement and there was about a half inch of water in the tray under the unit.

It appeared that the pressure relief valve was slowly expelling dribbles of water out the discharge pipe. I did some research and didn't realize that you are suppose to drain a couple of cups of water out of the relief valve every year. I annually flush sediment out of the heater but never knew about this PM measure.

After flushing a couple of cups out of the valve the leaking stopped. My question is should I change the valve or let it ride? I know it's not that expensive but I don't want to mess with it unnecessarily.

One note. The other day I replaced cartridges in 3 leaking faucets. By cutting off this pressure escape point in the water system could this have increased back pressure in the water tank causing this release?

The AO Smith is about 5 years old and the faucets were leaking for almost as long.

 

[CT18]

I would not recommend draining it from the relief valve. I have seen them leak afterwards. If you need to drain it from the drain on the tank.

 

[clarkgriswold]

I didn't drain the tank. I just purged 2 cups of water from the valve. When I drain the tank to flush sediment I always use the drain on the tank.

Still looking for an answer to the change or not change the valve question.

 

[Helper Dave]

If you've got a tray and a water sensor, I'd say just leave it for now. If it leaks again, change it out.

T&P valves are something you should either maintain regularly, per the manufacturer's recommendations, or never at all. Using one after years can cause it to leak, so you just make a problem for yourself.

But you've got safety measures in place, so keep an eye on it.

 

[House Doc]

The T&P valve is a spring loaded valve with a rubber washer. It has a cartridge to open it if the water temp is too high, and the spring is set to open if the pressure is too high. You can buy a pressure gage at most hardware or big box store. You can attach it to any hose bib, or in the laundry room. If your pressure is over 75 PSI (which is pretty high for most homes) a quick back pressure, such as turning off the tub valves quickly, could push the valve to open slightly, allowing some calcium buildup between the washer and seat. Flipping it as you have may have cleared it. I would say that 90% of plumbers go by the rule of "If it ain't broke...Don't fix it!"