High
24 on Ideal Response SE

Your boiler's temperature sensors have been incorrectly wired or swapped, causing the system to misread the water flow and preventing it from operating safely.

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.

Technical description

Flow and return sensors NTC and NTC2 reversed

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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