A mate of mine has a problem with his ideal classic ff240 boiler it fires up ok on demand for either DHW or CH although after approx 2 mins the boiler switches its self off and won't restart for a good 5 minutes. Every thing else seems to be working fine ie pump/motorised valve. The flow is starting to heat up prior to the boiler shutting down. Its a sealed heating system and the pressure was about 0.75 bar and when i increased the pressure it shot round to 2.5 bar quicker than you could blink which seemed a bit odd to me. Has anybody got any ideas before calling anybody round.