I would have thought if the continuity checks out on the gas valve, the engineer then tested the pcb? Install a multi-fit gas saver when you fit your new boiler. Combi can you even still get traditional boilers? These guys are the best don’t look anywhere else % satisfied and would recommend without hesitation. We offer -hour emergency service for major plumbing emergencies like burst pipes, overflowing toilets, leaking water heaters.