High Lockout
f015 on Intergas Xtreme 24

Your boiler has stopped working because its internal temperature sensor is not positioned or connected correctly, preventing it from heating your home safely.

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

Mounting fault sensor S1

What causes this fault?

This fault occurs when the boiler's main internal temperature sensor is not properly attached to the pipework or has disconnected from the control board. The system shuts down as a safety precaution because it can no longer accurately monitor the water temperature leaving the heat exchanger. The most common reasons are a loose mounting clip, a vibrating sensor, or a fault in the wiring harness connecting the components.

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

F014View →F016View →

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