The boiler strikes normally but after 5-6 minutes switches off, in just central heating and just hot water modes. Rads are hot, then cool down. For both heating and water it burns for a few minutes or not at all.
I have changed the pump, flushed the system, added cleaner. Flushed again and added inhibitor.
I have bled the rads from the top of the radiator and the bottom of the rads.
Still no change. Is it the pcb or the motorised valve or what?

Paul Lukas, January 2007

you probly have a bad aquastat(the sensor on the supply pipe or on the boiler) check by adjusting the dial on it higher, see if the boiler kicks on again, it also could be many other problems, check to make sure all the wires are making a good connection on your sensors and gas valve.

Andrew F., January 2007