Pilot light occasionally goes out during heating and hot water programme, it easily relights and is then ok for about 24 hours and the goes out again.
There is no problem with pilot light when in hot water only programme.

Derek, October 2013

Very odd. When was it last serviced? Odd because the boiler cannot differentiate between heating or hot water. As far as it is concerned it has only been instructed to light. Maybe the boiler doesn't go out when heating the water because it doesn't need to be on for as long so doesn't reach the point where it shuts down when in central heating mode.

Gas Safe Engineer in West Yorkshire, November 2013