High
004E on Navien NCB

Your boiler has detected a flame when it shouldn't be there, but it has already cleared the error itself and should be safe to continue running.

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

False-flame error (automatically cleared) displayed on the front panel when flame signal is detected continuously for 3 sec before combustion or during post-purge.

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

004EView →

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