Hi everyone i have a oil fire central unvented heating system the problem seems to be that the thermostat does not seem to be working as the system seems to be heating up to a temp where you cant put your hand on the pipe and when i move the thermostat the boiler does not kick out it also seem to be taking in air somewhere i was just wondering does this mean the stat it not working and is the boiler burning so much that it is turning the water to steam which is driving up my pressure thanks to anyone that reads this