Cold Radiator - help with TRV

[TattyTeddy]

Hi, I know there are so many "cold radiator" posts, but I am stuck before I get started.

I've got one cold radiator in the house, which is upstairs. A friend bled the radiators and said they seem to be ok but will probably need to be done again - I don't understand why, but even after this, the one radiator is still cold.

So...do I bleed all the radiators again or go for the stuck trv?

If it is a stuck trv, I've read alot of posts which say to tap by where the pins are - my problem is....how do i even get to this bit - the white plastic things dont come off...yes this is about my knowledge - I'm prepared to try anything, but dont want to break it

Many thanks in advance.

 

[kmeeres]

What make is the trv ?
Pix ?

 

[TattyTeddy]

Hi, I haven't got a clue - there doesn't seem to be anything written on it. Its white with a red dot on it and the numbers are IIII, III, II, I rather than 4, 3 etc. There is a little black/grey peg that is just to the right of the pointer which i move up and down bout half a cm, but not sure what this does. Otherwise there doesn't seem to be anyway of removing this. Sorry

 

[TattyTeddy]

I should have looked at the others in teh house first :s one has a name on the top which is comap (written in blue) and they are all the same.

 

[mickyg]

you sure it doesn't just screw off with a large silver screw? might be tight, could need a pair of grips.
does it look like this one? View media item 13268

 

[TattyTeddy]

Its not quite like that one - I've just taken a photo and will upload. Thx

 

[TattyTeddy]

Ok, this is what it looks like - hope this is of some help. Thanks again.

Untitled

• TattyTeddy
• 29 Jul 2009
• 1

[/img]

 

[kmeeres]

OK there is a big knurled nut under the black plastic.
This unscrews to remove the head unit anticlockwise looking from above.
You will then see the pin sticking up from the valve body.

 

[TattyTeddy]

and that pin shoud move? thx for your help with this.

 

[kmeeres]

Press down on the pin with a spoon it should go down then spring up when released, it will only have a very short travel.
If it does not spring up its stuck.

 

[TattyTeddy]

Ok, I took the one apart in teh kitchen as well so i can compare. Kitchen moves, the one in the bedroom definitely doesn't! This is such a tiny pin - do I need to tap the actual pin with a hammer or the nut that is around it?

 

[TattyTeddy]

Thought it couldn't hurt to tap all of it - hey presto the pin popped up. Thank you so so much for your help with this! It is so much appreciated. Thx