BoilerFaultCodesTechnical description
Sensor fault S5.
What causes this fault?
This fault occurs when the boiler's internal S5 temperature sensor stops sending a reliable signal to the main control board. It is usually caused by the sensor's electrical resistance falling outside of its normal range due to internal component failure or a loose connection in the wiring harness. Because the boiler can no longer accurately monitor heat levels, it shuts down as a safety precaution to prevent overheating.
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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