High
88 H......4....... on Ideal Isar M30 / M100

Your boiler has detected that the temperature monitoring system for the exhaust gases is not reading correctly, which means the boiler will stop working to ensure safety.

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

FLUE SENSOR

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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