How much does it cost to fix Navien error code 016?

Typical repair cost for the Navien 016 fault is £150-300 including labour.

016 High

Navien 016 Fault Code

Q: What does the Navien 016 fault code mean?

Your boiler has detected an issue related to the flow of water inside the unit, which has caused it to stop working to protect itself from potential overheating.

The Navien 016 fault code means: your boiler has detected an issue related to the flow of water inside the unit, which has caused it to stop working to protect itself from potential overheating.. It appears on 5 Navien models in our database.

Technical description: Error 016

Typical repair cost £150-300 (including labour)

Engineer required

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

Find a Gas Safe engineer

Search the official register for a qualified engineer in your area.

Gas Safe Register →

Boiler cover options

Avoid the next call-out bill

A cover plan would handle faults like 016: no call-out fees, no surprise bills.

Approved partner

Domestic Appliance Guard

Unlimited call-outs, 24/7 helpline, no price-hike promise

Get a quote →

Affiliate links. We may earn a commission at no extra cost to you.

Navien models that show the 016 fault code

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

Source

Navien 016 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