Danfoss valve isolation with no TVR

13 May 2008
Reaction score
United Kingdom
Hi all,

I want to remove an old radiator (replacing with a new one), it has Danfoss valve but I no longer have the TRV, it is in the off position but a bit of water still flows from the system. I cracked the nut to drain the radiator but stopped when i could feel the water was hot. Lockshield is closed at the other end.

The pin on the valve has can be pushed in about 3mm. Is that the valve complete closed off when I do that?

I read about some sort of decorating caps for Danfoss valves (and a trick with a 5p). Is that what I need to do here? Find something to push that pin in while I have the radiator off to stop water flow?

Photo of the valve below for reference.


FYI, my end goal will be draining the system and fitting a new rad/pipes/TRV in a different location, so i'm not worried if i wreck the valve. I just dont want to drain the whole system before I'm ready to put on the new rad.

Thanks the help!
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The term decorators cap, simply means a plastic cap that screws on to the valve and holds it closed so no water passes while you remove the radiator to decorate, you will need a new sensor anyway so just buy a valve they come with the decorators cap they are not expensive and you will have a new sensor

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