BoilerFaultCodes.com
12 High

Your boiler's internal thermometer for the central heating system has stopped working correctly, which means the system cannot monitor or control the water temperature.

Technical description: Failed heating sensor – issue with heating sensor and could need replacing
Typical repair cost: £90-160 (including labour)

Engineer required

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

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Parts commonly replaced

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