BoilerFaultCodesYour boiler has lost signal from the sensor that monitors the temperature outside your home, usually because of a wiring fault or a broken sensor.
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: External probe fault
What causes this fault?
This fault occurs when the boiler is no longer receiving a consistent electrical signal from the sensor located on the outside of your property. The most common reasons are that the external sensor has been damaged by the elements or the low-voltage wiring connecting it to the boiler has become loose or corroded.
This fault is often triggered during periods of extreme weather or heavy rain, which can cause moisture to enter the sensor casing and damage the internal components.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
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A boiler cover plan would cover faults like E10 — no call-out fees, no surprises.
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