High
T3.15A on Glow-worm Micron 60FF

Your boiler has stopped working because an internal electrical safety fuse has blown, cutting off power to the system's control board.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

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.

What the manual says

Manufacturer manual

Internal fuse

From this model's manual
Verified against the Glow Worm/Glow Worm Micron 30ff installation & service manual, page 29.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

Engineer required

This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Related fault codes

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All 23 fault codes on the Micron 60FF

Seeing a different code? Every code this model can display, in one place.

Burner Lit LEDBurner On neon offF4AFast Flashing (8Hz)Ignition LockoutIlluminated reset lightLED 1 (RESET) Constant LightLED 1 Fast Flashing (8Hz)LED 1 Slow Flashing (2Hz)LED 2 Burner LitLED 2 Fast Flashing (8Hz)NEON1NEON2NEON3NEON4NEON5NEON6Reset LED is litReset lightReset Light / OverheatSlow Flashing (2Hz)Software Error

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