How much does it cost to fix Johnson Starley error code EXHAUST SENSOR FAULT?

Typical repair cost for the Johnson Starley EXHAUST SENSOR FAULT fault is £120-220 including labour.

EXHAUST SENSOR FAULT High

Johnson Starley EXHAUST SENSOR FAULT Fault Code

Q: What does the Johnson Starley EXHAUST SENSOR FAULT fault code mean?

Your boiler has detected a problem with the sensor that monitors the safety of the exhaust gases and has shut down to prevent overheating.

Also written as EXHAUSTSENSORFAULT — same fault.

The Johnson Starley EXHAUST SENSOR FAULT fault code means: your boiler has detected a problem with the sensor that monitors the safety of the exhaust gases and has shut down to prevent overheating.. It appears on 1 Johnson Starley model in our database.

Technical description: Exhaust/flue sensor fault

Typical repair cost £120-220 (including labour)

Engineer required

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

Find a Gas Safe engineer

Search the official register for a qualified engineer in your area.

Gas Safe Register →

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.

J32 System ET Repair: £120-220

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 27 April 2026