Please HELP My 12 year old Trianco Eurostar combi 90 oil boiler starts ok but after about 10 mins the thermostat B trips and switches the boiler off. I have just turned the boiler on after its summer rest. There is no hot water. I dont think the central heating pump is running either. Is the central heating pump causing the problem or is it something else? I have checked water levels and they are ok and I bled the pipework on top of the boiler. Any suggestions would be much thanked.