Light Flashing Slow (once per second) indicates an ignition lockout or boiler overheat.
Light Flashing Fast (five times a second) there is a fault with the appliance.
Where the flashing light is it is also the reset button.
If the light is flashing slow then press and hold this button for 5 seconds to reset the system.
If the light is flashing fast then turn power to the boiler off, wait a few seconds, then turn power back on. This should reset boiler.
If the reset procedure fails or the fault contantly persists then you will need to call an engineer.
Hope this cures your problem.
Robin S
September 2008