Any suggestions!! I've just refilled my central heating system after moving a radiator. The radiators have all bled OK but when I turn the boiler on it only lasts 3 minutes before cutting out. When cooled it will start up again. Pump seems to be running fine. I'm assuming that air is in the boiler. It's a Boulter Economy oil boiler. Any ideas on how to bleed the boiler as I can't see any obvious bleeding points. Cheers.