I have to move the manual lever on the 3 way valve to get the heating to work.

Is it easy to replace? It is model number MSV 322

Neil Cromack, October 2008

Turn the heating stat right up 25`plus then turn the hot water cylinder stat right down that should turn the heating on. if not the 3way valve is shot. £59 @ Wickes Drain the system or isolate the valve and undo the nuts whip it off put the new one on. job done.

kevo, October 2008

Only if you know what you are doing, its a motorised valve and has probably gone. You should be able to take the valve off the top without disturbing the pipe it is connected to. Make sure you get EXACTLY the same one and it goes straight back on no probs.

JB, October 2008