I have water radiators where the in/out pipes are connected on the same side, and I can't find a guide online to explain how to disconnect those (all videos I find have 1 pipe on each side)

What I figured out so far:

  • Turn off the water main
  • Remove the white plastic knob and turn the valve clockwise to close the upper part of the pipes (picture in bottom left)
  • Nothing to do on the right side of the radiator (it seems sealed, picture bottom right)

What I don't understand is how to close the lower part of the pipes as it seems these will remain open once I remove the radiator

Can someone explain how to remove those types of radiators please?


enter image description here

  • Have you checked at the boiler? There's usually a manifold with cutoff valves there. Also, experiment with that valve at the bottom.
    – JACK
    Jun 25 at 12:10
  • Never seen a valve like that bottom left one before. Brief research says it's a "ventil valve" but I can't find any info on how it works. Hope would be that somehow it can turn off both of those two pipes. Not clear if or how. The top left valve would be redundant as far as your objective. Also I don't understand why you remove the knob before closing that.
    – jay613
    Jun 25 at 13:37

You are correct for the top valve.

For that bottom one, use the brass "screw" on the left to close the valve opening into the radiator - it closes the radiator pipe connection.

Then open the drain cock on the bottom right of the rad and crack one of the top joints.

Put some protection down as the fluid can be dirty black and stains better than any stain you can purchase...

See this post on another site for a similar explanation and a picture... https://www.plumbersforums.net/threads/flow-and-return-going-into-one-valve.46614/

  • @jay613 it is a combined bypass valve with shut-off - at least the one I saw a long time ago. Think of a cone that will go towards the radiator to shut that pipe and can be drawn back to allow an amount of "cross" flow.
    – Solar Mike
    Jun 25 at 13:36
  • Sorry I deleted my question just as you were answering it. I began to find some documentation (not in English) that explains the valve. Aligns with what you say but not crystal clear on if/how the two pipes from the floor can be shut off.
    – jay613
    Jun 25 at 13:39
  • Ah I think I've got it. It's like a variable monoflo. The bottom valve balances flow through the radiator with bypass flow between the two pipes. You cannot and should not "turn off" those two pipes. If you remove the rad the bottom valve must remain in full bypass mode. That's achieved by turning that screw, which "turns off" the right hand port of the 4-way valve. Then you need to turn off the top port (with the top valve) and then the bottom valve becomes pure bypass. A lot of guesswork here.
    – jay613
    Jun 25 at 13:58
  • Thanks a lot guys. Can you check my update with the detailed procedure to confirm if I'm understanding correctly?
    – Max
    Jun 26 at 15:03
  • Seems good to me. Not clear how exactly you "close" in step 2, but there aren't that many possibilities so you'll figure it out. You should check after removal that all the other radiators work.
    – jay613
    Jun 26 at 19:32

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