High
LED 4 on Ferroli Arean

Your boiler's temperature sensors are signalling that they cannot properly detect or regulate the heat, which is preventing the system from firing up your heating or hot water.

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

Sensor (34) or (42) calling for heat

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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