One cold radiator - tried everything!!

9 Nov 2012
Reaction score
United Kingdom
Hi all,
I have one cold radiator - the bathroom one.
I have searched the internet for a solution, tried them, but still no joy.

All other radiators work fine. Combi boiler is fine, water pressure is at 2. I have already changed the lock shield and TRV, both are open and TVR pin is not stuck in any way. Rad has been emptied and re-filled, bled but still no heat in either pipe or the rad.

Lost for what to do next? Any suggestions would be great help.

Thanks a lot,
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Turn the valves off and remove the rad and flush through with a hose.

Remember to switch off combi.

Get a bucket and slowly open one valve at a time, to see if they are blocked.

Hope this helps rob
You have not done "everything" !

You have not read the FAQs in this site and done the bucket test!

I have missed the bucket test!
The flow in value obviously works as it re fills after being emptied,radiator has been emptied and therefore is not blocked,i guess I need to test the trv value side?
Thank you all
Have you tried closing some of the other rads a little to see if it's a balance issue? Also, was this system changed to a combi at some point, just wondering if the rad was plumbed in to come on with the water and when they switched it over they did something daft like connecting it to cold? (I had to tell a guy who change my boiler that the mystery pipe he found was for the bathroom rad).
Yes test both sides, Trv and lockshield.

If they both flow, there must be another problem within the system.

Hope this helps rob
Thanks,I can see how the inflow side will work,cut the trv side value will definitely have pressure coming out?just with it being the return flow?sorry if it's a simple question,not done anything like this I need boiler on or off when doing this?
Water doesn't know if it's in the flow or return pipe, it's just relative to the boiler/pump. If there's somewhere for it to go (like an open valve on the return and no pressure from the flow), it will go there.
the lock shield side valve has pressure and flows.
the tvr side - when i shut off the lockshield side and open tvr side nothing! I guess the blockage is in here.
What are the next steps, is there way of telling where the blockage is? and how to unblock?!

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