High
F.76 on Glow-worm Energy System

Your boiler has detected an internal safety issue within its main heating component and has shut itself down to prevent any damage or danger.

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

The safety cut-out in the primary heat exchanger is defective

From this model's manual
Verified against the Glow Worm Energy System installation & service manual, page 35.
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

F.75View →F.77View →

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