Hi, I wonder if anyone can help. I have no problem with hot water from my combi, but when I put the heating on the pump runs however there is no burner. I thought it was the PCB as the variable resistor had gone open cct. I replaced this and the heating worked for a time but has now stopped again. So far I have checked micro-switches and aqua-stat, could there be anything else that would stop the heating only? Thanks
