High Lockout
L45 on Ideal HP290

Your boiler has identified that the internal fan is incompatible or incorrectly configured, causing the system to shut down for safety.

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

Wrong Fan Fitted

What causes this fault?

This fault occurs when the boiler's control chip fails to recognize the specific fan installed in the unit. The most common reason is a communication error between the fan and the main circuit board, often caused by the wrong part being installed during a repair or a software mismatch on the board itself.

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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