High
5.2.15 Error 517 on Navien NCB 40 HE

Your boiler has detected that its internal configuration settings have not been set correctly, causing it to stop operating.

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

Are the DIP S/W on the PCB properly set?

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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