Reply To: TP valves

The Tank TP valves Reply To: TP valves


KULTULZ wrote:

palerider wrote:

Ok, got the pressure gauge and put it on the outside hose bib nearest the main water pipe, and the downstairs shop sink near the water heater. I would’ve put it in the drain valve, but as it’s reading over 140 psi I think the problem is obvious. I opened the screw on the house’s pressure regulator three times, then ran water for a couple minutes and waited. the first time the operating pressure was around 40, but with 10 minutes or so the static pressure came back to 140. I’ve opened the regulator a total of at least five or six turns now, operating pressure is about 22, but the static still returns to 140.

Question is, is this because my regulator is shot, or because my water heaters (no expansion tank) is just re-pressurizing the system? If it’s the latter, does that mean my thermostats are not shutting off the heat when they’re supposed to, i.e. replace them?


It sounds like the PRV is bad, but the pressure check should be with WH power off and it’s water temp @ ambient room temp to exclude the possibility of false readings due to thermal expansion. Take the pressure reading, record, re-power WH and leave test gauge on for twenty-four hours to see if thermal expansion events raises the test reading.

If your system has a pressure reducing valve, consider it as a closed system and the expansion tank is needed regardless

When setting the TET air pressure, it has to be either isolated from the system (cut-off ball valve) or not yet installed on bench or water pressure released and TET drained to check previously installed tank.

(2lbs below house pressure).

Hope that made sense… 😯



The TET air pressure is set the same as the house water pressure (WH contents set to room ambient air temp).

I gave the pressure setting for a well pressure tank… 😯

Getting hard to find good help nowadays… 😕

Water Heater Rescue

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