For the last couple of months, every once in a while my boiler (and the heating) has stayed on after the Hive Heating schedule says it should have gone off.
What I have got used to doing is physically switching the boiler off for a couple of hours as this generally cleared the problem, and half filing it away in my head as a software problem.
It happened yesterday morning as I was waiting at home for the British Gas to turn up and give the boiler its annual maintenance check up. He investigated and found it was caused by a valve sticking. The valve was replaced and all is well.
I never tire in work of berating people for assuming that any and all problems relate to IT and warning them to entertain the possibility that the issue at hand may be more prosaic.
Hoist by my own petard.