Hi all. I have a Potterton Suprema 40 boiler which is misbehaving. It turns off and on again once every few minutes, even when room stat is calling for constant heat. Then once every little while it’ll lockout - always in the morning, sometimes precipitated by servere pipe knocking all around the system. Once reset it’ll fire up, but the short cycling continues. I’ve done a bit of reading but the other threads don’t seem to cover these problems. Does it sound like the PCB problem? Or overheat stat maybe?