if the pressure gauge drops below about 0.7 it wih shut down due to low water level if it keeps loosing water there must be a leak some where in the heating system. if your boiler gos out on windy days sounds like wind blowing down the flue putting out boiler.
hi-spec plumbing
November 2006
I can answer this question...
What is causing my vokera boiler to stop in windy weather?