High Lockout
E13 on Intergas Combi Compact HRE SB

Your boiler has detected a problem with the sensor that monitors exhaust fumes, causing the unit to shut down for safety.

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 S4 defective

What causes this fault?

This fault occurs when the boiler's internal safety system loses communication with the sensor that monitors the temperature of the exhaust fumes. It is usually caused by a physical failure of the sensor's internal components or loose electrical connections in the wiring harness. When the boiler cannot verify if the exhaust gases are at a safe temperature, it will stop running immediately to prevent potential heat damage.

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

E05View →E12View →

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