Thanks for the reply. I have checked the small tank and it seems ok. The reason for the overflow was what sounded like air being pushed into the small tank from the boiler, that is when the boiler switches off. It seems to happen about every 4 to 8 weeks.
Hi The boiler is a pottington supreme. The gurgling noise coming from the header tank overflowed last night out of the overflow pipe. Hope this helps. Brian.
Hi I have this problem with my heating system. I'm getting air blowback into the header tank which knocks off the boiler, ie flashing red light.
Any suggestions would be appreciated.