Emergency
762 on Navien NCB-28LDWE

Your boiler has detected that the flue pipe responsible for safely venting exhaust gases outside has become loose or disconnected.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Act immediately

Turn off your boiler and stop using gas appliances. Call a Gas Safe engineer now. This fault can be dangerous if ignored.

What the manual says

Manufacturer manual

The vent installation detector switch will detect if the vent pipe is not fully inserted, and the boiler may not operate.

From this model's manual
Verified against the Navien Ncb 28ldwe installation & service manual.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

Engineer required

This is a emergency severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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