Hi, I have the above boiler system, on sat i removed a radiator upstairs, and replaced it with another one, but instead of draining the system down , i cheated and emptied the resevoir in the loft until it was empty, this stopping any more water getting to the radiator, after fitting the radiator, i let the resevoir fill back up again to check for leaks, all is well, but now the boiler will not fire back up, when the system is cool, it will run for around 3 minutes until the exit pipe is warm, and then it shuts off, it will not relight until the system has cooled, the lights on the boiler show a non volatile lockout, i have tried bleeding the radiators but there doesn't seem to be much air in there, any other ideas, or bleeding processes I can go through.
Gaz.
Gaz.