DIY Doctor UK DIY Forums

Hi, l have radiator that won't heat, l have changed the thermostatic valve which is fitted in what l assume is the flow side because there is some heat in the feed pipe and fully bleed the system and know that there is no air within the radiator.
I shut off both sides of the radiator opened the bleed valve and fitted a funnel with pipe to a bucket, then opened the outlet return valve which is cold l get good pressure coming out of the bleed hole, if l then close the outlet valve and open the inlet valve which is warm l only get low water pressure out of the bleed hole.
So it appears that the feed pipe pressure is lower that the return pipe pressue yet the radiator use to work!?
All the other radiators work fine and this one is not the furthest away.
Any ideas ?

kjones,
Possibly an air lock, if you can up the setting on the pump try this first. Or turn off all other radiators and see if that will shift it.
end

Possibly a blockage in the flow pipework or manifold.

htg