High Lockout
4 red flashes on Baxi EcoBlue Heat

Your boiler's fan is not spinning or communicating correctly with the system, preventing the boiler 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

Fan fault

What causes this fault?

This fault occurs when the boiler's control system detects that the fan is not spinning at the required speed to safely clear exhaust gases. The most common reasons are a mechanical failure of the fan motor, a buildup of debris blocking the blades, or a communication error caused by a faulty circuit board.

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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