How much does it cost to fix Navien error code E47?

Typical repair cost for the Navien E47 fault is £120-200 including labour.

E47 High

Navien E47 Fault Code

Q: What does the Navien E47 fault code mean?

Your boiler is struggling to accurately measure how much water is inside the system, which is preventing it from firing up safely.

The Navien E47 fault code means: your boiler is struggling to accurately measure how much water is inside the system, which is preventing it from firing up safely.. It appears on 6 Navien models in our database.

Technical description: Water pressure sensor error

Typical repair cost £120-200 (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 E47 fault code

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

NCB Repair: £150-250
NCB 28 HE Repair: £120-200
NCB 35 HE Repair: £120-200
NCB 40 HE Repair: £120-200
NCB H Repair: £120-200
NHB 29 Repair: £120-200

Source

Navien E47 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