Our boiler stopped working last night. We had a minor panic, tried to relight it (the pilot light was out), failed, tried a bit more, failed some more. So we considered the fact that it was Saturday night, and that the heating would go off shortly anyway, and went to bed.
Got up to a chilly house (why do our boilers never fail in the summer!), switched on an electric heater (one heater doesn't heat a 4 bed house very well though!) and Heather set about calling plumbers.
We just had the guy around. Sunday callout charge is £75/hour plus VAT. He knew what was wrong within minutes. Replaced the thermocouple (a £8 part), put everything back together and invoiced us for just under £100.
I'm seriously considering re-training to be a plumber! However he did say it was about 10 years training to become a full CORGI registered plumber...