One rad staying cold

[nclegeorge]

I managed to drill through the wall and a CH pipe downstairs. (my detector did not pick up the pipe - I am aware that these detectors are not entirely reliable and am normally very careful - not this time though!) I closed all stop valves to stop leak. Emergency plumber came and fitted a distance piece of pipework and fixed the leak. He said that I would have to bleed rads later - to which I agreed.

Later noticed that hot water would not fire up in boiler. Insurance maintenance engineer came out and said that there had been a lot of air in the boiler and got hot water on again.
However the rad nearest to the affected drilled CH pipe stays very cold as does the affected pipework - both pipes and both sides of the repair.
The latter engineer said to bleed rads for 10 days.
Done that - little air came out.
Also I have shut off some of the rads upstairs and ran the CH to try and shift an air lock if that is the problem. Bleeding did not get any air out.

Suggestions?

 

[TCCHeating]

Turn off all rads apart from the cold one. Also turn off the bypass valve (if you have an s plan). This should then push any air out.

 

[nclegeorge]

Thanks for prompt reply
Do I turn all rads off (except the cold one) at both the TRV and the fixed valve and run CH?
Will I have to bleed air from the cold rad?

 

[TCCHeating]

You just need to turn them off at one side to stop the flow. Then run the ch only, with just the cold rad fully open.

If the rad gets hot, then you will need to bleed the trapped air that you have released from the top of the rad.

If you still cannot get the rad hot, you will need to do the 'bucket test', which is explained in the faq section at the top of the forum.

 

[nclegeorge]

Sorry for delay in replying

I bBled rads a number of times -all ok

Thanks to all