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Radiator knob spins endlessly - how do I turn it off?

thericky Member Posts: 4
edited February 2020 in Radiant Heating
Moved into a 100-year-old house. Never had radiators before. These things are OLD. There’s one room that gets super hot at night so I’m trying to turn the radiator off in there. But the knob just spins forever, never stopping or turning it off.

I have a boiler in the basement so I believe this is steam heat.

What do I do to fix this?

Pics attached. Thanks!


    JUGHNE Member Posts: 10,785
    Show us both ends of the radiator....full height.....all parts.
    Some pictures of the boiler also......back up and include all piping.
  • mattmia2
    mattmia2 Member Posts: 8,382
    We would need to see the other end and the top of that end to say for sure, but I think that is hot water. I think I see a hot water bleeder valve at the top of the radiator on the end with the valve.

    If it is hot water, you will need to take the pressure off the system and drain it to below that valve to take it apart and see if it can be fixed. It is also possible that valve is any of a number of odball designs and isn't just and ordinary globe valve.

  • Brewbeer
    Brewbeer Member Posts: 616
    You can cover the radiator to reduce its heat output while you are figuring out a way to turn it off.
    Hydronics inspired homeowner with self-designed high efficiency low temperature baseboard system and professionally installed mod-con boiler with indirect DHW. My system design thread: http://forum.heatinghelp.com/discussion/154385
    System Photo: https://us.v-cdn.net/5021738/uploads/FileUpload/79/451e1f19a1e5b345e0951fbe1ff6ca.jpg
  • Icarus
    Icarus Member Posts: 143
    edited February 2020
    Hot water...as Mattmia2 says, repair the valve. You also should determine if it is just the knob that is spinning and not the valve stem. Take the knob off and gently turn the stem clockwise with a pliers. If it moves, turn it all the way until it stops, and the radiator should get cold. That said, there is a chance of the stem leaking around the packing. If it drips a bit, try to tighten the packing nut a little bit.

    As was suggested, cover the rad with a blanket until spring if you have to, and then rebuild it in the summer when you can afford to be with out heat if something goes south.

    And no, the blanket won’t catch fire, the rad is only ~180F at it’s hottest.

  • thericky
    thericky Member Posts: 4
    The stem spins too. So yeah, blanket for now. Will fix after winter. Thanks!
  • mattmia2
    mattmia2 Member Posts: 8,382
    If you push or pull while turning it might catch and do something. We don't know if that is just a globe valve or is some sort of gate or ball or even bellows valve unless someone recognizes it. The name on it might help identify it.
    JUGHNE Member Posts: 10,785
    Some valves of that vintage would only turn 180 degrees from fully open to closed with a small opening to keep water circulating for freeze prevention.
    The stops can easily break off allowing a completely spin.
    If you just park the valve in the "closed" setting it might work.
    With the word closed facing the radiator.

    Heavy quilts or rugs will slow down the heat if needed.

    You most likely have to have the valve changed, not a major deal.
    It will require draining the system down. While the system is drained down would be a good time to change all the air bleeders on all the rads. The one you pictured looks pretty painted up. You would have to drain down to change those anyway...... PITA to do for one failed bleeder that might not always close after bleeding air.
    Now is also a good time to find any other valves that might need attention in the spring.

    What do you have for an air expansion tank? Pictures, it might be up at the ceiling.
    What temp is the boiler running at? That can be turned down a little.