[villages07]

Originally Posted by DangeloInspections

Always glad to help.
Sometimes folks are quick to assume the T & P valve is bad, when actually it is doing it's proper job. If the Thermal Expansion tank is waterlogged the expanding water has no place to go and the relief valve will open just a bit to allow it to escape.

If a person is going to change out the expansion tank and needs to partially drain down the tank anyway, it is good practice to also replace the "leaking"
T & P valve also, as repeated opening can weaken the spring and seals inside. The cost is not much more. When doing so make sure you buy the correct rating T & P valve, as Watts makes many different types and it is easy to buy the wrong one as many will "fit" but only one will be correct. Take a picture of the tag or just bring the old one with you to make sure.......

Frank D'Angelo

Frank.... exactly what happened to us. Replaced the TP valve and that did not fully fix the problem. It was the thermal expansion tank...it was listing off to the side since it was full of water. House was about six years old...many of these blue tanks have had the bladder bust at 5-7 years. Newer tanks are good for 7+ years.