i was told the same for my boiler!! what with me being a tight *rs* i got a diaphram from ebay for it and fitted it. easy enough to do too... and it worked..
yes the professionals know what there doing and i dont want to take work away from them but spending £10 on ebay might save you £350!!. if it doesnt work then uve only lost a tenner eh??
then you call the men in the know!!
mark wilson
December 2008