How much does it cost to fix Alpha error code 78?

Typical repair cost for the Alpha 78 fault is £150-300 including labour.

78 Emergency

Alpha 78 Fault Code

Q: What does the Alpha 78 fault code mean?

Your boiler has detected an issue with the internal component that manages the gas supply, meaning it has safely switched itself off to prevent unsafe operation.

The Alpha 78 fault code means: your boiler has detected an issue with the internal component that manages the gas supply, meaning it has safely switched itself off to prevent unsafe operation.. It appears on 10 Alpha models in our database.

Technical description: Anomaly on the gas valve control - An anomaly on the gas valve control is detected

Typical repair cost £150-300 (including labour)

Engineer required

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

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Alpha models that show the 78 fault code

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

Source

Alpha 78 fault code information on this page is sourced and cross-checked against the official Alpha service / installation manuals for each affected model.

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