Cold water recently started flowing out of my tank into the cold water pvc that exits to the side of the house - it was running continuously for at least an hour until I notice my lawn was saturated. I turned off the water at the street for about 5 min and then turned it back on. It hasn't repeated the problem. What would cause this?


Here's a couple of pics for a look at the pvc and tank. The pvc shown top right of the tank was the one that was continuously draining to the side of the house.

Top of the Tank
[drive.google.com]

PVC Drain on side of the house
[drive.google.com]

Thank you for your help!
IS



Edited 1 times.

It is a pressure relief valve, so something, possibly a failing pressure regulating valve caused the pressure to rise above its setting.

As hj said or a bad thermal expansion tank

Thanks. Can you explain why turning the water off and back on reset this valve so that it stopped? Is this always a result of a failing valve and what kind of cost would be involved in replacing it?

you lowered the pressure by shutting the water for a while.
you need to know for sure what caused the pressure to rise before you start changing things.
i would get a pressure gauge that screws onto a hose valve and check pressures a few times before proceeding with any repairs.

That would only discharge about a cup of water to eliminate the expanded water.