One Cold Radiator - help!

4 Jan 2012
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United Kingdom
I have one cold radiator downstairs, the pipes are also cold.

I have bled it, turned other radiators off to just have that one on to see if it will work but still stone cold.

Its not a TRV valve but took the plastic cap off both ends and hammered the valves to start them but still cold. I also turned the pips on both ends anticlockwise as they were a bit stiff but still nothing.

We bled the radiator system fully a couple of months back when we had a new radiator put in and I think it worked afterwards but then stopped working shortly afterwards.

Heating and hot water are fine and its a combi boiler.

I have tried bleeding the radiator and removed approx half a cup of water to see if the pipes would get warm but still cold.

We have got the tap in the loft shut to stop a water overflow into the system as recommended by a plumber who fitted the new radiator. Would that have any impact?
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This will only work if they are newer rads with a blanking and a bleed valve nut at each end.

Shut the rad valve at each end off.
Open the bleed valve leave open until it stops draining.
Now remove the nut on the end. Water will need catching in bucket.
Fit a 15mm elbow into the rad and piece of copper on the other end to direct it into a bucket.
Open one valve only until water flows. Inch it open slowly always ready to shut it off. Then repeat with the valve on the otherside. This may draw air out of the pipes but will also make sure pipes and valves are not blocked.


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