Moved into a house with a completely new CH system installed approx 12 months ago. Condenser boiler with pressurised hot cylinder. All rads working initially.
Had most of the rads turned right down over summer, mainly so we can keep the towel rad on in the bathroom.
Now the bedroom rad doesn't really warm up, even though all other rads do.
TRV on full (5/5)
Valve pin under TRV moves up and down freely
Inlet valve gets quite hot
Outlet (TRV) gets lukewarm
Rad gets lukewarm, mostly at the top. Cold at bottom
Bled it - no air in rad.
I suspected it was an airlock so did the usual trick of turning all rads off except bedroom one, and turning thermostat up. Left for 3 hrs
Bedroom rad got hot all over, suggesting the fluid can get through somehow
Then when I turn all the other rads back on the bedroom rad goes back to being lukewarm.