Radiator problem

[flame20]

I'm currently decorating what is going to be the nursery in our house and we have a problem with the radiator in that room.

All the other radiators in the house work fine and heat up with no problems, and this is the only one with a problem. It never gets any hotter than lukewarm.

The valve to the right (thermostatic valve??) is red hot to touch when heating is on, yet radiator is not. And the valve on the left (lockshield valve??) is cold always.

Can anyone suggest something that might help me, as I'd rather try and sort this out before I have to pay someone to come out and fix it?

* I've bled all the radiators in the house - no probs there.
* I've tried turning all other radiators off except the problem one - nothing changes.
* I've taken it off the wall and emptied out any water and put it back on, bled it, etc - still no changes.
* I've been up in the loft and checked the water tanks. Both are full and there appears to be no problems there.

Can anyone please suggest anything else to help me?

Thanking you in advance for anything you offer...

 

[D_Hailsham]

The valve to the right (thermostatic valve??) is red hot to touch when heating is on, yet radiator is not. And the valve on the left (lockshield valve??) is cold always.

Two things come to mind: stuck TRV or lockshield closed. The LS valve is easy to check.

Remove the head from the TRV - no water will come out - and you will see a brass pin. You should be able to press this down, using a piece or wood, and it will spring back up again. If this works, the rad should get hot. If not, give the valve body a thump with your handy piece of wood and try again. If all fails you will have to replace the TRV.