E30 Emergency

Johnson Starley E30 Fault Code

The Johnson Starley E30 fault code means: your boiler has sensed that the exhaust gases are getting too hot and has shut down as a safety precaution.. 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: Flue gas temperature overheat
Typical repair cost £150-450 (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 E30 fault code

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

Source

Johnson Starley E30 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