i would do a series of checks first
are you capable of taking boiler front casing off
can you drop down the fascia panel
you should now be able to see the hydraulic section
youll need the boiler manual to identify the divertor valve
& DHW FLOW VALVE
when opening a DHW tap can you see the plunger on DHW FLOW VALVE push the microswitch
if plunger does not move then diaphragm needs replacing
a very fiddly job
if plunger does move all the way
could be DHW microswitch or pcb
easy fixes
manwithnoname, May 2011
