Hi I have been asked to look at a domestic heating system, the boiler is Johnson stanley, the programmer is drayton lp112 and the 3 port valve is an old acl.
When the programmer is advanced for both heating and or hot water nothing happens, there is no movement of the zone valve and the boiler does not fire, the zone valve does not appear to be seized as it will drive with a direct feed to it and the pump the same.
I am told they had a plumber out and he changed the programmer but also managed to fuse things and blow all the fuses, i have replaced them and the programmer lights up but does not give any output or a run signal for anything.
Any idea's guy's?? please

shaun, September 2010

put a link between live on the programmer backplate and the heating or hot water demand and turn any thermostats right up or link them out. if it works then faulty timer (or thermostat) if not the wiring aint right.

Ian, September 2010