: the pop-off valve on my water heater keeps going off . ive replaced it and the top thermostat. any suggestions on a fix?:First try checking the incoming pressure with a simple pressure gauge,If the pressure seems to befine (80psi or less) then check to make sure you do not have a closed loop system. This is usually the case if you have a circulating pump.Look for a check valve on the incoming cold side of the heater or possibly a pressure reducing valve or backflow preventer.All of these devices cancreate a closed loop system therefore allowing thermal expansion to exist. If this is the case simply add an expansion tank inside the loop to absorb the expansion. I hope this Info helps
