High
L- on Ideal Isar System

Your boiler has switched itself off for safety and is displaying a 'lockout' status, which will be accompanied by a second flashing code to tell you exactly what is wrong.

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

Boiler is in lockout for a specific error. Display will be blinking, alternating with a number or letter to show which error is detected.

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

L9View →LFView →

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