How much does it cost to fix Navien error code 762?

Typical repair cost for the Navien 762 fault is £100-200 including labour.

762 High

Navien 762 Fault Code

Q: What does the Navien 762 fault code mean?

Your boiler has detected that the flue pipe attached to the unit is not pushed in securely enough, causing it to block the system's safety sensors.

The Navien 762 fault code means: your boiler has detected that the flue pipe attached to the unit is not pushed in securely enough, causing it to block the system's safety sensors.. It appears on 3 Navien models in our database.

Technical description: Vent installation detector error; vent pipe not inserted to sufficient depth

Typical repair cost £100-200 (including labour)

Engineer required

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

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Navien models that show the 762 fault code

Click a model for the full fault code list and model-specific repair notes.

Source

Navien 762 fault code information on this page is sourced and cross-checked against the official Navien service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026