One radiator not heating up

[vero]

Help please!
I have switched the heating back on, and one of the radiators is not heating up. I suspect a stuck TRV, but can't manage to take the cover off.
There is no brand that I can read on the knob, pictures attached.
Anyone has any idea how to take this off please?
Thank you!

 

[vero]

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• vero
• 20 Oct 2014
• 1

Untitled

• vero
• 20 Oct 2014
• 1

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[D_Hailsham]

Turn the chrome knurled nut, immediately below the black part, (top towards you) to remove the head. No water will come out.

This will expose a pin. Press on it and release. It should move toward the valve and then spring out. If it won't move, tap the valve body with a hammer and it might release. If the pin moves but only comes up slowly, lubricate it with silicon lubricant - NOT WD40 which will rot the seals.

 

[vero]

thank you for this, I have (finally) managed to get round to take the cover off.
The pin is sticking out and not moving.
I have tried tapping the valve body and the pin with a hammer, but it's not moving at all!

Untitled

• vero
• 11 Dec 2014
• 1

 

[andytw]

If the pin is 'Out' then that is good. The movement on the pins is quite small.
Can you push it in and have it spring back to you. Total movement will be about 5mm.
Having ensured it is moving freely in and out, and without re-fitting the head, does the radiator still not get warm

andytw

 

[vero]

hi, no it doesn't move at all

 

[andytw]

hi, no it doesn't move at all

Then it is fair to assume it is is stuck.
Apply a bit of WD40, push down and pull up until is is moving freely.
You can push down with the flat of a screwdriver blade and pull up with a pair of pliers.
BE CAREFUL, when pulling upwards, that you restrict how much movement you allow as you can pull the pin right out. In other words don't just grab it and heave, just try and ease it up a LITTLE BIT.

Did you press down quite firmly as they are do give quite a bit of resistance even when working correctly ?

If in doubt get a reference of the feeling and measurements of a working valve from another of your radiators.

andytw

andytw

 

[JohnD]

a good tip when pressing is to put the bowl of a soupspoon in the palm of your hand. This enables you to press straight down, the pin will not bend sideways, and you can apply good pressure.

I hadn't heard about WD40 attacking the seals. What are they made of?

 

[vero]

mmm interestingly enough, I just had a look at another similar radiator's valve... and the pin doesn't move at all either... am I being thick here?

 

[andytw]

mmm interestingly enough, I just had a look at another similar radiator's valve... and the pin doesn't move at all either... am I being thick here?

It will need a fair push. It will hurt if you were to use just your finger !
Not sure a finger would do it.