many new gorton d vents maybe bad

johnnyh13

I have d valves on some radiators on all floors. my question is had to return to supply house.com couple d valves for not closing and opening too soon as soon as heat goes off. I moved the good valve to radiators where bad valves were and it works fine. question is what would cause air valve to open as soon as boiler shuts down and radiator is still red hot.am I just getting bad valves from this place? also had to hit valves sometimes for it to close all the way and returned them now got problem of venting too soon when hot.forgot to mention also changed main vents to #2

nicholas bonham-carter

When the burner shuts down, all the steam condenses fairly rapidly, leaving a vacuum. the vents will all open very quickly to let air back into the system.
For vents not closing, check the pressure, as if it is above 2 psi, the vent may have trouble closing all the way. Another possibility is that debris from dirty boiler water may have been thrown up into the system, lodging in the vent, preventing it from shutting all the way.--NBC