For a couple of months had intermittent hot/cold water. Boiler keeps turning itself off. Plumber hasn't been able to fix despite cleaning heat exchanger, checked pump, removed and cleaned diverter valve, new thermostat - but no joy. Heating seems to work ok. Plumber won't return our calls any more. Decided to join British Gas yearly checkup scheme. BG man visited this morning. Wouldn't touch our boiler. Said we would be refunded our £200+ already paid to BG. Said SIME parts no longer available, our pipes are too small and we have to move flue. Didn't want to take our boiler on. Boiler only 5 years old. Said we would have to spend £2,500 for new boiler and fitting. Does this sound right? Any plumbers in the St Albans area willing to take repair?