BoilerFaultCodesYour boiler has lost communication with the sensor that monitors the outdoor temperature, which means it cannot automatically adjust its settings based on the weather.
This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.
Technical description: Outside Sensor Fault
What causes this fault?
This fault occurs when the boiler's main control board loses the electrical signal from the sensor located on the exterior of your home. The most common reasons are a breakdown in the sensor's internal circuitry due to moisture ingress or damage to the thin communication wires connecting the sensor to the boiler.
This fault is often more frequent during autumn and winter as extreme temperature shifts or high winds can expose pre-existing damage to external wiring or the sensor housing itself.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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A boiler cover plan would cover faults like 4.10 — no call-out fees, no surprises.
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