BoilerFaultCodesPotterton A1 Fault Code
The Potterton A1 fault code means: your boiler is flagging a safety issue because its flue terminal is installed too close to an opening like a window or air vent, which could allow dangerous exhaust gases to enter your home.. It appears on 1 Potterton model in our database.
Technical description: Directly below an opening, air brick, opening windows, etc.
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 A1 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Potterton A1 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