30 BF Emergency

Sime 30 BF Fault Code

Also written as 30BF — same fault.

The Sime 30 BF fault code means: your boiler has detected an issue with the air intake or exhaust flue system, which prevents it from operating safely.. It appears on 1 Sime 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: 30 BF
Typical repair cost £150-300 (including labour)

Engineer required

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

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Sime models that show the 30 BF fault code

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

Source

Sime 30 BF fault code information on this page is sourced and cross-checked against the official Sime service / installation manuals for each affected model.

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