John Sevinsky wrote:
Yeah, but I'm seeing this gradual pressure increase al the time, even
when the hot water tank is not being heated. The tank is heated from a
boiler with an oil burner, and I defnintely know when that is running.

John

ok then I agree, look at the regulator valve..

when you think about it, that valve has a tough job, since water is not
compressable, if the valve has even the smallest leak, the pressure
will gradually build up.

Mark