some of my central heating radiators are not as hot as they should be as the pipes to each ends are not the same temperatures , one end is very hot but not the other end , therefore not getting the full heating . How can i fix it please ?

si, December 2008

There should be a difference in temperature between the water going in and the water going out - the heat loss is going into the room! Radiators should ideally be "balanced" so that each has a temperature fall of about 10 deg C. and each radiator in the chain gets a share of the available heat. See...
http://www.miketheboilerman.com/balancing.htm

To get more heat out you might increase the temperature control on your boiler to make the water slightly hotter and adjust the speed of the circulating pump to get it round the system a little quicker.

If radiators are hot at the bottom but colder at the top they need bleeding to let any trapped air out.

Peccavi, December 2008

It could take ages.You may have to half shut down any rads that are getting really hot,which in turn should help the ones that are struggling.Make sure any that you need hotter have both valves turned on fully as the lockshields are turned down sometimes.Some rads may be sludged up but try the above first.Hopefully this will help get the ones you really want hotter to work better.

Tony S, December 2008