As part of a revamp to the downstairs cloakroom I re-routed the radiator pipes up and over the doorway (meant I had a clean wall for the shower cubicle). So they now do an inverted "U". Since doing that the radiator has not got warm when the system is on, all others are OK. They have been bled (many times and the valves are open). If I remove a bleed screw, eventually warm water will come out - so the feed is OK. I have fitted an automatic bleed as high as I can up the wall on the return pipe, that has had no effect.
Do I just accept that the additional pipe run up and over the room (approximately 9m out [3m up, 3m across and 3m down] out and back) is now just too much for my pump and simply fit a more powerful central heating pump?
Anything else I can try first?
Cheers
Peter