Three cold rads

[CKJDJK]

In my house I have a mixture of pipe bore sizes. Occasionally I get a cold rad. I did remove each rad and flush with a hose but I found in one of them a plug of rad seal at the thermostic valve. To get this to flow took a few adjustment of the valves to make the plug move. Once it moved all ok. Since then I just shut all the rads down and run each rad at full bore to shift the crud. It worked for me. For awhile.
If you can, remove each rad and flush with a high power hose then refit. Same with the boiler. Reconnect then flush with a flushing additive. then bleed and run each rad in turn. Then adjust each rads lock shield valve. If all working redose with inhibitor. Adjust inlet rad valves to heat required. You could power flush but removal and pressure blast each rad is best. Don't forget to remove and clean any filters fitted.

 

[knighty]

you've already tried turning the other rads off so this post doesn't really help you.. but good info for other people

old plumber (really old) once showed me how to balance the system... with the radiators cold go around and turn each rad off (at the tap you don't normally turn) then turn it on 1/4 of a turn

turn the heating on... go around and check which radiators are hot... any that are noticeably colder turn them up an extra 1/4 of a turn and keep checking


sounds obvious when someone tells you, but I'd never thought about doing that before

 

[gaz1]