B1 Emergency

Potterton B1 Fault Code

The Potterton B1 fault code means: your boiler is flagging a safety concern because the flue terminal is positioned too close to an opening like a window or air vent, which could allow dangerous gases to enter your home.. It appears on 1 Potterton 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: Above an opening, air brick, opening window etc.
Typical repair cost £200-500 (including labour)

Engineer required

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

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Potterton models that show the B1 fault code

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

Source

Potterton B1 fault code information on this page is sourced and cross-checked against the official Potterton service / installation manuals for each affected model.

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