Thanks for the advice.
checked the boiler - Potterton profile 30
I have replaced the valve today. Had to increase the speed to 3 for the first couple of times to start the boiler (when the pump was cold)
Then as the pump got warmer it was OK. So not so sure yet whether this was the valve...
Hi
My CH boiler occasionally does not start. I've noticed that when I increase pump speed to 3 (normal setting 2) the boiler will immediately start and is OK for some time then. And I can reduce the speed to normal 2.
Seems like the pump gets the signal to start but not starting and then...