Medium
001 on Navien NCB

Your boiler has detected that the internal pump is running while the burner is inactive, which can sometimes happen due to a temporary system glitch.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

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This fault should be looked at by a Gas Safe engineer within the next week or two. It may get worse if left.

Technical description

Error 001

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Related fault codes

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