Thermostat problem?

[DJ6676]

Hi

The radiator in my son's room wont work when set at levels 1-4, but works fine when set to level 5.

This is a problem as it's either cold or to hot. Is this a thermo problem or could anything else be causing it?

All other rads are working fine.

Thanks in advance.

 

[linkyplumb]

Unscrew the head of the trv and see if the pin is moving in and out freely.

 

[DJ6676]

Unscrew the head of the trv and see if the pin is moving in and out freely.

Thanks - Did this, pin seemed to be ok so worked fine after I put it back together.

 

[vicvapour]

Put a little put of lithium grease on the pin and "work it in" if you can, if it get stuck again, replace the whole TRV.