How much does it cost to fix Navien error code 004E?

Typical repair cost for the Navien 004E fault is £120-250 including labour.

004E High

Navien 004E Fault Code

Q: What does the Navien 004E fault code mean?

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.

The Navien 004E fault code means: 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.. It appears on 6 Navien models in our database.

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.

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 004E fault code

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

Source

Navien 004E 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