I recently drained my central heating system to carry out some DIY and after refilling it my towel rail in the bathroom does not get hot. I've looked at other posts on here and have so far tried turning off all other radiators and putting the heating on but it remains cold. If I have the heating on and open the towel rail bleed valve water runs out and the towel rail gets warm. I've bled all the other radiators in the house and there doesn't appear to be any air in the system.
Any ideas much appreciated.
Any ideas much appreciated.