Perhaps its already been mentioned but does the HW valve open and the lever go floppy when you select HW only?
If that happens but the boiler does not come on then the fault is likely to be that the microswitch inside is not being operated. Thats more often mechanical wear rather then by the switch it self failing.
Tony[/quote
not sure dude,so fecking confused

now,hot water fri with just the c/h on,this morning nothing,pump set on 3,emersion heater switched on and the c/h and h/w set to come on at 4am,6am all the pipes and valves are red hot,even the boiler in the kitchen is red hot all over,but anything below the valve are coldish,there the pipe that comes up threw the floor boards and goes into the tank at the bottom with the little screw vent on top id hot half way up then it gets cold againall the thermostats are set on max,ie the one in below the stairs/the boiler its self and the tank one which is held on with elastic wrapped around the tank.
now there are 2 valves,a pipe comes down and splits into 2,one into each valve,which one is the h/w one and what is the other one for,i remember the plumber saying something about if u push the little lever across it should slowley come back,neither of mine does this.what are the settings on them,i think i put mines to manual the other night and got some hot water,
so tomorrow im going to take the screw out of the pump,replace,see if i can get the covers off the valves,fiddle about in there a bit,spraw with wd40 and see what that does.
alse there are a few turn/stop red things,there all open,so that should be right.
back to the emersion heater,i know its supposed to be for emergancies when the boiler dosent work but mines does feck all.
im sure we have been over all this before but need a fresh look at it,if all else fails then its call in time for the plumber,but the last time he came,he said to make sure nothing was on,i know because the pipes get hot but how is he suposed to see the problem if all the pipes are cold.
thanks for bearing with me forum gurus,