LED 2 Fast Flashing (8Hz) High

Glow-worm LED 2 Fast Flashing (8Hz) Fault Code

Also written as LED2FASTFLASHING8HZ — same fault.

The Glow-worm LED 2 Fast Flashing (8Hz) fault code means: your boiler has detected an internal electrical or computer error and has stopped working for safety.. It appears on 4 Glow-worm models in our database.

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description: Other Errors

What causes the Glow-worm LED 2 Fast Flashing (8Hz) fault?

This fault occurs when the boiler's central control unit suffers a critical communication failure or an internal electrical short. It usually means the main circuit board can no longer safely monitor the boiler's components, so it shuts down the system instantly to prevent damage. The most common reason is age-related wear on the control board's solder points or a surge in the electrical supply.

Typical repair cost £180-350 (including labour)

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Glow-worm models that show the LED 2 Fast Flashing (8Hz) fault code

Click a model for the full fault code list and model-specific repair notes.

Source

Glow-worm LED 2 Fast Flashing (8Hz) fault code information on this page is sourced and cross-checked against the official Glow-worm service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026