Hello, hopefully posting this in the right place. Have a Baxi duo-tec boiler that is not firing up for water or heating. The green 'hot water' led lights, showing that there is demand for hot water when the hot tap is turned on, but boiler does not even attempt to fire up. Heating initially worked, but the heating led does not even light up when the central heating is turned on. However, when put into service mode, the boiler fires up fine. PCB board has be swapped out. No error codes displayed. Any suggests great fully received, as am at a bit of a loss now. Many thanks.