Hi, have you managed to find a solution to your problem? I drained my system last night and now it won't work!!
I don't have a header tank in the loft but the cylinder in the airing cupboard does have a little tank at the top which is full.
To drain the system, i turned off the mains to the house.. drained everything, turned the mains back on and i've no water in the radiators. Bled them this morning and 3 of radiators are now full of water but the rest don't have air or water coming out of them.
When i turn the Heating on.. it fires up fine, the pump starts going and after about 30 seconds, the boiler has a fit and shuts off then the pump starts making funny noises.
I've turned everything off and unplugged the pump to stop it dying.. i keep bleeding the radiators but nothing is coming out yet (apart from the 3 with water in them).. anyone got any idea's? It's an old system.. a glow worm ultimate boiler and no pressure guages so i assume it's not pressurised.
Mark
February 2008