My plastic drain valve had a small leak so I replaced it with a new copper valve. I had to drain the tank to replace the valve and it appeared to be fixed. A few hours later water started to pour out of the pressure relief valve. I tried to snap the valve shut again and the water stopped leaking so I turned the boiler back on and checked it 30 min later and the valve was leaking again. Should I replace the pressure relief valve now? It wasn't leaking before why would it be leaking now that I've fixed the drain valve?

The T&P valve will leak if either the water temperature is too high or if the water pressure gets too high.
Before replacing the T&P Valve Check the water pressure should be between 40-60 psi, and also check the temperature setting at should be at 120 degrees F. if both OK then you replace the T&P valve failure of the T&P valve will cause explosion open the link watch the clip, Thanks.

John


Water Heater Blast - YouTube

Hi Kandis

If you touched the temperature and pressure relief valve (T&P valve) to drain the water heater then that would have disturbed the T&P valve washer and these usually don't reset well, so definitely replace the T&P valve in this case.

If you didn't touch the T&P valve to drain the water heater AND your water heater has an expansion tank associated with it then it is probably the expansion tank that has ruptured and really needs to be replaced... although you'll also want to replace the T&P valve as it has been disturbed, too!

Finally, check the pressure and temperature setting of your water heater as suggested by John... may need to reset the temperature or even replace a pressure reducing valve (PRV) if your pressure exceeds 80 P.S.I. OK?

No matter what, it certainly sounds like you have no choice but to replace the T&P valve... ;)

Good luck!

Mark