BoilerFaultCodesTechnical 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.
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