BoilerFaultCodesYour boiler has lost connection to its outdoor temperature sensor, meaning it may not heat your home as efficiently as usual.
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: Outdoor sensor not detected.
What causes this fault?
This fault occurs when the boiler's main control board can no longer communicate with the external weather sensor normally mounted on an outside wall. The most common reasons are a break in the connecting wire, water ingress into the sensor casing, or the sensor itself failing due to age.
This issue is often discovered during the first cold snap of autumn when the boiler attempts to use outdoor temperature data to adjust its heating curve.
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 CC — no call-out fees, no surprises.
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