We have this boiler and have checked the manual for you. The fault indicator button is to the right of the flame indicator button. To re set press the button for 5 seconds if the fault indicator is flashing slowly. If the fault indicator is flashing fast,turn the power off then on at the mains. When this happened to me a few weeks ago we realised that I'd accidentally knocked the gas mains tap downstairs which meant the boiler cut out completely.It will also cut out if the water pressure is too low.It should operate between 1 and 2. Hope that might help you to sort it out.