How much does it cost to fix Johnson Starley error code 46?

Typical repair cost for the Johnson Starley 46 fault is £120-£210 including labour.

46 High

Johnson Starley 46 Fault Code

Q: What does the Johnson Starley 46 fault code mean?

Your boiler has shut down because it cannot detect a signal from the sensor that monitors exhaust gases, preventing it from running safely.

The Johnson Starley 46 fault code means: your boiler has shut down because it cannot detect a signal from the sensor that monitors exhaust gases, preventing it from running safely.. It appears on 10 Johnson Starley models in our database.

Technical description: Flue gas temperature sensor open circuit. Temperature sensor not connected or failed. Check wiring connections. Check sensor continuity.

Typical repair cost £120-£210 (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 46 fault code

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

Source

Johnson Starley 46 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