High
E353 on Navien NCB CE

Your boiler has detected an issue with how it manages water flow and pressure, which means it cannot safely produce hot water for your taps or home.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description

DHW Heat Exchanger: Water leaks; Low temperature water in the heat exchanger; Water pressure sensor: Unable to detect or measure changes of water pressure

Engineer required

This is a high 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

E351View →E352View →

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