COLD RADIATORS UPSTAIRS

[PG]

I have a central heating problem where one radiator on the top floor is always completely cold. All other radiators are hot.
It is a gas CH system with a Glow-Worm boiler on the ground floor, hot water tank on the 1st floor and problem radiator on the 2nd floor.

I tried bleeding it but only water came out.

The pressure gauge attached to the heating paraphernalia in the airing cupboard was 1.2 bar, I increased it to about 1.5 but it made no difference.
The pump in the airing cupboard is already set to max.

A few weeks after noticing this problem, another rad on the top floor also suffered the same fate.

I tried turning off the TRVs on pretty much all other rads and set the problematic rads' TRVs to max but still no joy. Also tried turning the temp control on the boiler to max.

After reading other posts I'm going to remove the tops of the TRVs and check for a stuck pin this evening.
However, I'm not convinced that it's a TRV failure as the pipes supplying these rads are also cold. Is it common for 2 TRVs to fail within weeks of each other?

If there are no stuck pins, does anyone else have any suggestions? I suspect it could be a motorised valve failure but I know nothing about these. If it is a motorised valve failure then why would one upstairs rad work but the other wouldn't?

I'll probably have to call out a heating engineer for this one but I'm hoping, with your good advice, I can avoid it.

Many thanks in advance for any suggestions.

 

[Bahco]

Read post no 8 FAQs.

 

[PG]

OK, panic over.

It turned out that it was a faulty TRV. Or TRV head to be exact.
The radiator heated up as soon as I removed the TRV.

Does anyone know if I have to replace it using the same make of TRV head (ie. Myson) ?. I'm not impressed with two of these failing in such a short time.
Can anyone recommend another reliable brand which I can get for around £8 (assuming it will fit on the valve)?.

On removing the plastic head, I noticed the pin on the radiator valve was not stuck but the plastic pin on the underside of the TRV head was very hard to push in.
On a normal functioning TRV at room temp the plastic pin in the head is loose.

So luckily I will only need to replace the TRV head rather than the metal valve component too.

Cheers!

 

[Bahco]

Trvs are not universal so buy the same make and just use the head.

If you cannot locate you will have to change the whole TRV and you will need a rad spanner (Allen key)