Please help! Removed radiator valve and can't get it back on!

ThisIsWeird

There is another possibility that could explain both situations - the rad not coming on, and the TRV head being difficult to replace. The TRV head may have failed in the 'closed' position.

Laura, could you try two things, please?

1) Use something to help you push the valve pin downwards - it may be that you are just not pushing it firmly enough (the silvery valve pin can be seen in that still from the video above). It's hard to push down with just your thumb or finger as it'll hurt! So, perhaps a teaspoon placed over it, and then push firmly down? It should move smoothly, around 6-odd mm, and 'bottom-out' firmly. When released, it should 'pop' up instantly. Does it?

2) Look at the underside of the TRV 'head' as shown in the pic you posted, observe the white plastic bit in the middle, and see if it goes in and out as you turn the head from '5' to 'frost' - max to min, and back again. Does it?

RainbowLaura

ThisIsWeird said:

There is another possibility that could explain both situations - the rad not coming on, and the TRV head being difficult to replace. The TRV head may have failed in the 'closed' position.

Laura, could you try two things, please?

1) Use something to help you push the valve pin downwards - it may be that you are just not pushing it firmly enough (the silvery valve pin can be seen in that still from the video above). It's hard to push down with just your thumb or finger as it'll hurt! So, perhaps a teaspoon placed over it, and then push firmly down? It should move smoothly, around 6-odd mm, and 'bottom-out' firmly. When released, it should 'pop' up instantly. Does it?

2) Look at the underside of the TRV 'head' as shown in the pic you posted, observe the white plastic bit in the middle, and see if it goes in and out as you turn the head from '5' to 'frost' - max to min, and back again. Does it?

Ahh, this is interesting - I have now managed to make the pin move up and down, but the underside of the TRV head doesn't do a thing when I twist it from max to min. Looks like I'll be ordering a new one of those then, and hopefully problem solved!

You are all so helpful, thanks so much

Mutton_Geoff

RainbowLaura said:

the underside of the TRV head doesn't do a thing when I twist it from max to min. Looks like I'll be ordering a new one of those then, and hopefully problem solved!

It won't be easy to see that side working as there are hidden springs etc. I doubt very much it's faulty and you won't be able to buy that part on it's own anyhow. See how it behaves when you refit it.

Belenus

Replacement heads for most TRVs are usually widely available on eBay and elsewhere and there should be no need to buy an entire unit if the head has failed. I have had a few TRV heads fail and have easily purchased a replacement.

Laura, what make is your TRV?

As posted above, if the white plastic centre of the head does not move when you turn the dial then the sensor has failed and is not usually fixable. They don't last forever but replacements should cost you only about £10 to £20 depending on the make.

It is very unlikely that you need to replace the valve itself unless it is leaking. A sticking pin can usually be fixed by manipulation or application of a lubricant as posted above.

Mutton_Geoff

Belenus said:

Replacement heads for most TRVs are usually widely available on eBay and elsewhere

I learned something new. Even found it - https://www.heatingcontrolsonline.co.uk/acl-drayton-lifestyle-rt212-replacement-head-p-690.html

I think I'd get it back on and test it before spending money though.

Belenus

Geoff, that is a good price although they want £2.99 plus VAT for delivery so it totals £14.21..

Laura, if you are sure your valve head has failed, check other suppliers and also eBay and Amazon etc and see if you can beat that price when delivery is added.

I usually find eBay the cheapest but that can vary.

Eldi_Dos

In the second picture of the base of the sensor head there are numbers 10 to 28 ,I believe, what are the significance of them?

Belenus

Laura, it is possible that a non Drayton head will suit you as most TRVs have the same size thread. Some may need an adapter so check before buying.

Amazon have some universal heads from about £6.99 with free delivery. I can't advise you on their suitability or quality and life expectancy so check carefully. Most of the heads in the links below get generally good reviews.

Link.

Link.

Mutton_Geoff

Eldi_Dos said:

In the second picture of the base of the sensor head there are numbers 10 to 28 ,I believe, what are the significance of them?

Calibration of temperature. 10 to 28C

diystarter7

Hi OP

No wonder you could not marry the two together.

Most heads and valves are standard sizes.

If I was you and you did not want to waste time - order a cheap one (I think you get the whole set only from about 7/8 quid)

and try there see if it matches and if it don't and even if you take it home, as long as the packaging is good etc I've never had a prob with screwfix returning items.

Thaks