The push rod on the diverter valve is coming up quickly and is firm. It's reiggering the microswitch that is lighting the demand lights. I have replaced the microswitch but nothing changes.
I can't find a reference to a Relay in the manual. I wonder now if one of the pcb's has failed...
After searching the forum for a while I'm beginning to home in on the causes of my problem but I'm looking for some confirmation that I'm not barking up completely the wrong tree. I am after all not a plumber.
Yesterday all was well with the boiler. Today, opening any tap on the hot water...