I have a FB-38 Bell and Gossett pressure reducing valve in my radiator system (a contractor just installed it 4 days ago) and the label on the valve says “Set at 12 lbs”.
Unfortunately, I awoke this morning to find water on the floor beside the boiler and still dripping (the pressure relief valve in action). The boiler's pressure gauge showed 30psi and the temp was 140F. I turned the thermostat down and allowed everything to cool during the day.
This evening (with the water temp below 60F) I closed off the system’s main water feed valve, bled the pressure down to 10psi. and then re-opened the main water valve. Within about 10 or 20 seconds, without adding heat to the system, the pressure gauge moved up to 20psi.
Isn't the function of this "pressure reducing valve' to keep the pressure at or below 12psi? Or, am I thinking about this wrong? It seems to me like they've installed a defective pressure reducing valve but I honestly don't claim to know very much about this stuff. Am I on the right track?
Sincere thanks! -Rob