My boiler stopped 'firing up' on Monday 24th April and an appointment was arranged for the next day at 3pm. That was quick enough for me because I was out for most of Monday. The engineer arrived on time (in fact, two minutes early!), diagnosed the problem in minutes, discussed my options, checked availability of the necessary part (fan), went out to collect the part and returned to fit it. All of this took about an hour. He also corrected two items of shoddy workmanship in the original installation of the boiler. Both matters were safety hazards. One would have been dangerous if the boiler had been placed in a used bedroom instead of my kitchen extension.