There is probably an air lock. If you have the system at 1.5 bar try loosening the small plastic cap on the automatic air vent on the top of the pump but do not remove it. If you turn the power off to the boiler then turn it back on again then the pump will run for about 1 minute. This should allow any air in the pump to escape. Also check that the heating flow and return valves, the cold water inlet and hot water outlet valves and gas valve are open. Check all radiator valves are open and thermostats are turned up. Bleed any air out out of the radiators. Top the sytem pressure back up to 1.5 bar and turn the power off then on again. Try bleeding the radiators again and top up the pressure if needed. Hopefully this will solve the problem. I am assuming that when you restart the boiler the gas ignites and the boiler is cutting out on overheat. If the gas is not igniting then the F1 code means that there could be problems with ignition unit, fan or flame sensing electrode which will need a corgi registered technician to look at this for you. I would really recommend that you get a reputable gas installer in to look at any fault on a gas appliance as it is not just the gas that can be dangerous. If the system is overheating this can be dangerous, especially on a pressurised system such as this. It may cost quite a bit but with a good company you will get some sort of warranty and some peace of mind. I have passed my corgi course but do not work with boilers regularly and I sometimes have problems fault finding so for Joe Public to do this is very difficult. Try and find a contractor who specialises in boiler maintenance.
Good luck.
martin whyte, May 2007
