High
Lights: On Off Flash on Potterton Promax Heat Only

Your boiler has detected that the incoming electricity supply has been wired backwards at the point of connection, which prevents it from operating safely.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

What the manual says

Manufacturer manual

Live & Neutral Reversed. Incoming Live and Neutral reversed.

From this model's manual
Verified against the Potterton Boiler Promax Heatonlyheinstallation installation & service manual.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

Engineer required

This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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