vokera excell 80 won't fire up when hot water tap or is turned on. can hear the switch click; pilot light is lit. it does fire up when the casing is removed. diaphragms replaced last year.

tom h, August 2009

it worked! cleaned out switch with specialist tool (vacuum cleaner with drinking straw taped to nozzle) and that did the trick. it was quite sooty/dusty up there.

tom h, August 2009

great ricky, thanks for the advice. i already checked fan and it looks like its working ok. think it could be the flue pressure diff switch, as it seemed to do an exaggerated version of the fault when i disconnected one of its pipes. will try to clean it out, or replace it. do you know of anyone good for servicing boilers in london area? i've had some trouble with cowboys who don't have a clue on repairs but are very good at giving quotes for a new boiler!

tomh, August 2009

sounds like the flow pressure diferential switch is faulty.or the fan not working properly.(they are situated at top of boiler.switch is normaly enclosed in plastic casing with pipe into flue.) go to vokera site and you can download a work shop manual free of charge. hope this helps. ricky

ricky, August 2009

sorry, that's meant to read "when hot water tap or heating is turned on". it does work if the front cover is loosened.

tom h, August 2009