when my potterton 24 boiler reaches temperature it goes out for 10 seconds and reignites ,this continues. I have replaced pcb/safety thermostate/flame sensing eloctrode. But problem is still there

l spencer, March 2008

do you have thrmostatic radiator valves on all your radiators? this may be the reason!
If this is a combi boiler then you should have at least one radiator fitted with a normal wheel valve to allow circulation for the pump in case you shut all thermostatic valves on radiators.
The one with the wheel valve needs to be open at all times.

gary, March 2008