One of the radiators in my apartment has a knob that I can turn to turn the radiator on/off:

The bottom of a radiator with a knob

But the other one doesn't have a knob in that place:

The bottom of a radiator without a knob

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.

  • 1
    Did you try a vise-grip and gentle lever action on the knob? The gentle part is what makes the difference between "fixed", "crap, it's stuck" and "holy expletive, the place is flood"
    – Jeffrey
    Nov 23, 2023 at 19:27
  • There may be a manual shutoff for this zone, if so throttle that valve to get the heat you want.
    – Gil
    Nov 23, 2023 at 22:09
  • As others have said, the valve is stuck and that's why the knob not there. As many here may know, a trick when using those types of valves is that when you open the valve, back off the full open position by 1/8 or 1/4 turn. This way if/when it gets stuck, you can try moving it in both directions, which may help free it up.
    – SteveSh
    Nov 24, 2023 at 13:39

3 Answers 3


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

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