We have an Alpha CD32C combi boiler that's almost 4 years old. Because of its location in the loft and the length of the pipe runs, it's always taken about a minute to get hot water out of the tap but it's gradually got worse. First noticed it around christmas but put it down to the very cold weather and much colder than normal water supply, but now we can't get any hot water at all unless the heating is on.
Heating off, turn tap on and burner fails to ignite but there's no flashing lights or any indication of any fault. Heating on, turn tap on and get hot water as normal. Any idea what's wrong guys?
Cheers