I replaced the PCB on my ariston Euro Combi boiler after going through the flow chart. It worked for two weeks but the boiler has broken down again. There are three micro switches on top of the diverter valve if i make the centre switch the boiler operates on heating only. if all three are made the boiler does not work at all.
Any ideas

F. Coulson, February 2011

I would have a look at a central heating circulation problem...check that the flow switch (within the clear plastic cover) is making. It has two thin tubes feeding it, one below and one to the right

Jon, February 2011

before changing pcb i always ring relevant tech help line they should be able to give an accurate assessment(often flow charts can be misleading) also any electronic part is susceptable to failure in the first few weeks it still may be pcb

brian, February 2011