One Radiator not heating

[phartley]

HI. I have one radiator in the house of 8 not heating. I have removed twice and flush through replacing the TRV value also. After refitting both times the radiator gets hot but after two days it stops getting warm.

I;ve checked and theres no air and the pipework is all copper with no changes to the system. The system is 15 years old. Can anyone suggest anything please?

 

[Stu-B]

What type of system/boiler is it and where on the system is this radiator? How big is the house? Maybe the pump is running weak

 

[SimonG]

Have you balanced the radiators?

What happens if you turn other radiators off?