High
AA2222 on Ariston Genus 27

Your boiler has detected that a internal water sensor is stuck in the 'on' position even when the pump isn't running, preventing the system from starting 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.

Technical description

The flow switch does not open

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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