--_-_ t1_irmw16q wrote on October 9, 2022 at 2:08 PM

Reply to comment by mule_roany_mare in Your annual reminder that if your apartment has a radiator, don't open and close the valve. This can create condensation in the system causing a knocking sound. Radiators are designed to be used with a series of open windows to balance heat. by emeyer94

If you have a two pipe system you're better off just shutting the valves. Two pipe valves are designed to be used repeatedly and to be partially closed to throttle the heat. If you see multiple valves, only touch the one that's closest to your radiator on the steam supply side, though. That one is the one for you to use, the others are just to isolate the radiator for repairs and will probably start leaking if you wear out the seals by repeated use.