Recent content by coggy101

Yeah, this seems to be the PCB fault. I changed mine recently and it fixed the problem. The card is easy enough to change out. Isolate the power at the distribution board and locally! Remove the steel housing, unscrew the 3 black screws on the plastic cover by the temperature dial. Unscrew the...

Even if you have 230V on the zone valve, check the small wheel at the side. It should rotate to a flat side when driven open. Sometimes they will fail to open even with the 230V applied. This water blockage will stall the water flow through the boiler and cause an overheat trip.