One Cold radiator in lounge please help

[bootgaz]

I had a new combi boiler installed last summer. Everything has been working fine until recently when a large radiator in the lounge has become cold. It has a TRV which i exposed and found the pin to be stuck, this was released but the rad was still luke warm.

The pipe that runs from upstairs to the TRV side of the rad is cold but the pipe that runs from upstairs to the other side of the rad is warm.

I have turned all the TRV's to off on all the radiators downstairs to try and force heat to the rad but still nothing. Do you have to turn the valve off on the otherside of the radiator or just the TRV.

I have also noticed the rad downstairs also in the lounge nearest the boiler is still hot after i turned the TRV off .

Advice needed on what i have done and if its right and what to try next

 

[swidders]

I had a new combi boiler installed last summer. Everything has been working fine until recently when a large radiator in the lounge has become cold. It has a TRV which i exposed and found the pin to be stuck, this was released but the rad was still luke warm.

You have identified a fault

The pipe that runs from upstairs to the TRV side of the rad is cold but the pipe that runs from upstairs to the other side of the rad is warm.

It would be - there is no flow through it if the rad is cold

I have turned all the TRV's to off on all the radiators downstairs to try and force heat to the rad but still nothing.

You mean force water through the rad - this will make little difference

Do you have to turn the valve off on the otherside of the radiator or just the TRV.

just closing a TRV will prevent water flow through a rad

I have also noticed the rad downstairs also in the lounge nearest the boiler is still hot after i turned the TRV off .

The problem lies within one radiator - no others

Advice needed on what i have done and if its right and what to try next

Since you have relieved the pin on the sticking trv, try tapping it with a rubber mallet or piece of wood

If this doesn't solve the problem, open the valve at the other end half turn, by half turn (only a little at a time since you don't want to completely unbalance the system)