i have a firebird heatpac slimline oil fired boiler sighted outside, The problem is that it fires up runs for 1/2 an hour and then cuts out(being very hot) not to fire up again for 3-4 hours.all setting are calling for heat,my electician said the thermostat, so i changed that but no change. thanks to any one who can throw any light on the problem

dave, August 2010