How much does it cost to fix Main error code Bat?

Typical repair cost for the Main Bat fault is £120-200 including labour.

Bat High

Main Bat Fault Code

Q: What does the Main Bat fault code mean?

Your boiler is having trouble communicating with an external safety device, such as a carbon monoxide alarm or a specialized shut-off sensor, causing it to stop operating as a precaution.

Also written as BAT — same fault.

The Main Bat fault code means: your boiler is having trouble communicating with an external safety device, such as a carbon monoxide alarm or a specialized shut-off sensor, causing it to stop operating as a precaution.. It appears on 1 Main model in our database.

Technical description: Safety Assist accessory error

Typical repair cost £120-200 (including labour)

Engineer required

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

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Main models that show the Bat fault code

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

Insul 7 Repair: £120-200

Source

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

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