High Lockout
410 on Ideal Ideal Classic SE15P FF

Your boiler’s internal computer brain has developed a critical electronic fault and can no longer communicate with the rest of the system.

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

internal failure - electronic

What causes this fault?

This fault occurs when the boiler's main control board suffers a hardware failure, meaning it can no longer send or receive the signals needed to manage the heating process safely. The most common reason is age-related wear to the delicate electrical circuits on the board, though it can also be triggered by a sudden power surge or moisture getting into the control box.

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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