In fairness to all, we don't discuss pricing on the Wall. Thanks for your cooperation.
I had to replace a leaking expansion tank last week on a radiant heating system. I installed a new one with a 20psi charge and charged the system to 20psi. The water-feed valve was then shut off.
A few days later, I saw the pressure gauge reading of 60psi. Puzzled, I drained around 2+ quarts of water and the pressure went back down to 20psi.
Today, the pressure was high again, so I drained some more. The water temp varies from 100* to 140*.
This all seems wrong. What is happening here?
Steve from Newton, MA