High Lockout
E16 on Remeha Avanta 18V

Your boiler has detected an issue with the sensor that monitors exhaust gases, and it has shut down for safety purposes.

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

Flue gas sensor error

What causes this fault?

This fault occurs when the boiler's internal safety sensor detects that the exhaust gases are becoming too hot or if the sensor itself has developed an electrical failure. The most common reason is a buildup of debris or scale inside the main heat exchanger, which prevents heat from being transferred to your water and causes it to escape through the flue instead.

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.

Find a Gas Safe engineer
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Related fault codes

E5View →E6View →

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