High
neon flashing (Section B) on Potterton Performa System HE

Your boiler is struggling because the internal pump, which pushes water around your radiator system, is stuck or has stopped working correctly.

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.

Technical description

Pump check - CH system pressurised to 0.5 bar when cold. Pump jammed or faulty winding.

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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