One cold radiator

[jonny00stars]

Hi, I hope someone may be able to solve my mystery. I have one cold radiator on a combi boiler system. The other 6 radiators are nice and hot, but this one remains cold. It seems one side of the radiator is slightly warm but the other side (with the thermostat) is cold. I have read various posts on the forum and have taken the top of the thermostat valve and checked the valve, having done this the valve seems to be open but still no heat. Could the valve be sticking internally or be filled with "sludge". Any suggestions?

Many thanks

 

[seco services]

could be blocked sludge etc try shutting the other see if it clears it.

 

[jonny00stars]

I tried shutting the other radiators as suggested, but this had no effect. I then disconnected the thermostat valve (the one on the colder side of the radiator) and tested it was working by opening it into a tray... it worked OK and did not appear to be sludged up. I have re attached and tested to see if this cured the problem... it didn't. I have yet to try and do the same on the other side although I doubt this will be the source of the problem as the valve is warm, as is that side of the radiator. My next step is likely to be detaching the radiator completely and flushing it out with a hose. Any other suggestions?

 

[seco services]

did you open the otherside of rad to see if it flows out the rad end thats disconnected ?
did it flow from the valve at a descent rate ?

can you leave the trv top off as the valve may open/shut by hand but the thermostatic sensor maybe faulty.

 

[jonny00stars]

I didn't try opening the other valve to see if it flows out of the radiator as you suggested, but will try tonight.

The flow from the TRV is fine and I have left the top off the TRV to eliminate the risk of that being duff.

Would you recommend getting the system pressure flushed professionally... how much should this cost?

 

[jonny00stars]

Problem was solved by disconnecting the TRV, placing a tray under the now open end. I then opened the valve at the other end to flush water through and dislodge any gunge that had been stopping the water flowing.

Problem solved.