Hi all, just a bit of self-doubt here, have wired in a Worcester Bosch Greenstar ri boiler with three two port valves which feed HW, Rads and one underfloor heating circuit. The boiler hower is not firing although clearly has power to it. When the time clock calls for heat there is power at the sw terminal at the boiler and the pump starts the boiler just doesn't fire. I am not convinced the fan in the boiler is starting? have told the plumber it is now in his ball park but wondered if there is anything else I can check electrical wise, knackered PCB?