Error 125 High

Potterton Error 125 Fault Code

Also written as ERROR125 — same fault.

The Potterton Error 125 fault code means: your boiler is struggling to push water around your heating system, which means it cannot provide hot water or heating until the flow is restored.. It appears on 2 Potterton models in our database.

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.

Technical description: Primary circulation fault or pump failure
Typical repair cost £150-350 (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 Error 125 fault code

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

Source

Potterton Error 125 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 27 April 2026