70runner
New Member
City water, 3/4 supply line to Watts N45B PRV, then to twin softener system, to pressure gauge on outbound side of softener. Perhaps once every day or 2 I'll notice the pressure gauge at ~ 90psi. Opening a nearby faucet will bring the pressure down to the regulated 60psi level. I have two water heaters in the home, no expansion tanks. Is there a procedure to determine if the 90psi spike is caused by the city supply/defective PRV or thermal expansion in one/both of the water heaters?