High
L8 on Ideal Icos

Your boiler has detected an internal communication failure between its main computer and the system, meaning it needs a professional to reset or replace the electronics.

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

ALTERNATING 'L' '8' (REFER TO FRAME 68)

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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