Technical description
Flashes to indicate spark operation (stops after detection).
What causes this fault?
This indicator appears when the control board sends an electrical current to the ignition electrode to create a spark. It is a normal part of the starting process where the boiler attempts to light the gas to begin heating your home. If the light continues to flash without the boiler firing up, it usually means the spark is occurring but the gas is failing to ignite or the system cannot 'see' the flame.
DIY fix possible
Observe the light during start-upExpect the light to stop flashing once the flame is establishedNo action is required as this is normal operation