Emergency
E030 on Navien NCB CE

Your boiler is detecting an issue with water flow or heat levels, which could mean dangerous air or gas is trapped inside where it shouldn't be.

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.

Technical description

Primary Heat Exchanger/Secondary Heat Exchanger/DHW Heat Exchanger: Exhaust gas leaks; Overheating of water causes bubbling noises; Low temperature water in the heat exchanger

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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Related fault codes

E110View →

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