thermo couple no good or not in pilot flame correctly.
piolt flame too low
Colin Brooks, December 2008
no overheat on this boiler sounds just like a dirty pilot or faulty thermocouple
d....m, April 2005
Sounds like there is an overheat stat wired into the thermocouple and it is cutting out the pilot light because the boiler is overheating for some some reason , either low pressure of faulty pump
Steve, March 2005
edit
I can answer this question...
VULCAN CONTINENTAL BOILER - PILOT LIGHT KEEPS GOING OUT?
