It sounds like the temperature of the waetr bein g returned is higer vthan the thremostat will allow.This is likley to be due to the fact that onley a few of your radiators are expelling the heat.You need to find out why your radiators are not working. It is likely you have an air lock in that part of the central heating system.If you bled out the water from the ch system the temperature will drop in the remaining water.See if that solve the problem of it shutting down.
In difficult air lock sytems you can try leaving the outlet drain fully open on the radfiator and fit a hose to the garden.Ten fit a hoase connected to the waetr mai to the inlet on the central heating.The increased pressure from the water mains might just be enough to clear the air.Make sure all the valve are fully open first. Domnt forget when you nhave finished to add new protection fluids to the system.
You may find at the death you will need to fit an air bvleeder valve in the system.If so fit this as high in the system as possible If you live in a house,fit is upstairs.Often the central heating pipes will run into the airing cupboard up stairs. This might be a good pl;ace to cut into the 22mm pipe and fit a tee. Then and extended pioece opf 15 mm pipe as mhigh as you can gbet it and a bleeder valve on the top. You can actuall also buy automatic self bleeding valves but take care.. sometime these will also expel water and you might bet some damage to your ceilings.
Remember you might also have a blocked or partially blocked return pipe.You can email me direct if you wish on billsaint@btinternet.com
Bill saint, September 2008
