1 radiator running too hot

[Babytalkobsession]

Hi,

We have a combi boiler and we tend to leave the central heating on constant, and manually adjust the temp on the thermostat unit. Fine.

We have the thermostats on the radiators in the bedrooms set on 2 or 3 and those rooms are comfortable, apart from one where the radiator is just so hot! Turning the thermostat dial does nothing, it doesn't respond.

So if heating is on that room gets uncomfortably hot.

Does anyone know of anything we can do or is it a job for a plumber?

Thanks

show us a photo of the "thermostat dial" you mention please.

And of the knobs or valves at both ends of the radiator that gets too hot.

Is it in the same room as the wall thermostat?

Thanks for replying @pigletjohn
Apologies for not getting back to you sooner.

I'll attached some photos of the thermostat valve.

The thermostat for the central heating is a wireless one, it's never in the room with the faulty radiator. It's mainly in our lounge.

Here we go - when I say thermostat on the radiator I mean the twisty thing where you set 0-5

can't see a pic.

What make is it? How old?

Is it firmly attacked by the nut or collar underneath?

When you screw it downwards, do you feel a point where it meets resistance?

Do you know how to take the thermostatic head off so you can swap it with a similar valve?

Hi, I've taken it off and refitted it a couple of times to see if the connection wasn't right but has made no difference.

When turning it it stops at 5 and zero so it seems to be connected - it just doesn't impact the temp.

Not sure how old the radiator is, I'd guess at least 7 years (we've only been in the property for 2)

Thanks

Reattaching the pic

It looks like a Pegler Bulldog, a good valve. The one sold now seems to be a Bulldog 2.

First, take the thermostatic head off. Observe if there is a metal pin sticking up from the valve beneath. If not, it has presumably broken off and you will need a new valve. If there is a pin, apply half a drop of WD40 to the tip of the pin by dipping the point of a pencil into a jamjar where you have sprayed a bit. Put a soupspoon into the palm of your hand and see if you can press the pin down and it springs up.

If the pin is present and working, swap the head for an identical head from another valve in your house. If the valve then works, the head must have failed. You can probably buy a new Bulldog2 and swap the heads cheaper than buying a replacement valve complete, but ask Pegler if they are interchangeable, if not, order a replacement head.

Before removing or replacing a head, wind it fully up to its highest position to minimise pressure on the pin.

Yes!! thank you so much @pigletjohn you have saved us a call-out at this expensive time of year!

The pin was a bit sticky so sorted that, but still no joy. Swapped TRV with one from our bedroom and it's done the trick! So baby's room is perfect, ours is boiling ordered a new trv to replace. Job done!