High
C RY4 on Ferroli Arean

Your boiler has detected an internal communication error between its safety sensors and the fan, preventing it from safely starting up.

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

Relay not energised - Air pressure switch (43) not in NC position or miswired: check wiring; fan (16) at low speed remove jumper JP4

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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Related fault codes

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