EXHAUST SENSOR FAULT Emergency

Johnson Starley EXHAUST SENSOR FAULT Fault Code

Also written as EXHAUSTSENSORFAULT — same fault.

The Johnson Starley EXHAUST SENSOR FAULT fault code means: your boiler has detected an issue with the sensor that monitors the temperature of the gases leaving your flue, meaning it has shut down as a precaution to ensure safe operation.. It appears on 1 Johnson Starley model in our database.

Act immediately

Turn off your boiler and stop using gas appliances. Call a Gas Safe engineer now. This fault can be dangerous if ignored.

Technical description: Fault detected in the flue/exhaust temperature sensor
Typical repair cost £150-250 (including labour)

Engineer required

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

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Johnson Starley models that show the EXHAUST SENSOR FAULT fault code

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

Source

Johnson Starley EXHAUST SENSOR FAULT fault code information on this page is sourced and cross-checked against the official Johnson Starley service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026