How much does it cost to fix Navien error code E762?

Typical repair cost for the Navien E762 fault is £120-250 including labour.

E762 High

Navien E762 Fault Code

Q: What does the Navien E762 fault code mean?

Your boiler is struggling to detect the exhaust vent, likely because the flue pipe is not fitted securely or is the wrong size for your home.

The Navien E762 fault code means: your boiler is struggling to detect the exhaust vent, likely because the flue pipe is not fitted securely or is the wrong size for your home.. It appears on 4 Navien models in our database.

Technical description: Vent installation detector error; can appear if the vent pipe is not correctly sized or has not been inserted properly.

Typical repair cost £120-250 (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 E762 fault code

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

Source

Navien E762 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 27 April 2026