One of the radiators in my apartment has a knob that I can turn to turn the radiator on/off:
But the other one doesn't have a knob in that place:
How do I turn the second one off? I tried turning the bit that sticks out with plyers, but I can't get it to budge. It's really hot in the room with the second radiator so I'd like to turn it off.
I'm in Toronto, Canada.
I tried turning the bit that sticks out with plyers, but I can't get it to budge.
Turning that shaft is probably what the knob used to do, and its being seized up is probably why the knob is missing now: it was broken off trying to turn the shaft.
Fixing this is probably beyond your legal capability: the valve needs to be replaced or at least taken apart, and you'd have to shut down the heating system and drain/refill/other-heating-tech-skills the system to be able to fix the valve.
Tell the landlord about it, hope they'll fix it soon, and run room fans out the door or open the window to dump excess heat until then.
It looks lie it has been painted over. Scratch the paint around the knob and the nut under it. Then gently turn one way and the other, to break the paint. If it doesnt work then as mentioned in the other answer, it may need replacing.
Try when the heating is on, and when it's off. It may be less jammed at one temperature than the other. I have freed a stuck valve with a couple of drops of light (or penetrating) oil applied where the shaft enters the valve body, but that may have been a marginal case.
A small adjustable spanner is the best tool to buy, if you're buying.
If you can't budge it, insulate it by draping several layers of towels over it, with as much coverage as possible. Some radiators have nothing between "off" and "too hot", so I've done that in a few places
