After you draw off DHW the pumps cuts in to remove residual heat, but at times it continues to run and the boiler ignites as if the C/H is switched on.
Thanks very much,I have obtained a new PCB but not yet fitted it, meanwhile the problem seems to have subsided after
raising the cold bar pressure from 1.0 to 1.5.
Does this make sense, or is it just a coincidence.
