Saunier Duval pilot light keeps going off…?

Thanks Woodspeed - I guess by pilot I mean the green ignition light. It's a XEON model, brand new a year ago. We've had the engineers to look at it about eight times, they can't find a fault and have replaced two circuit boards and the little door over the control panel, but it's STILL switching off, and will not restart unless turned off at the mains, then on again. The engineers now insist it must be an external problem. Does that sound possible?

sjh2008
November 2008

Only fitted a year ago and it has a pilot????? Boilers for years have had electronic ignition.
However: maybe a s/h or older unit?
There is a heat sensor on the pilot - thermocouple. This may be faulty or not aligned in the flame properly. Part is £10-£15. May not be sealed properly in which case it can blow out. Fan can fail or stick, in which case it shuts down. These devices are for protection.

Woodspeed
October 2008