BoilerFaultCodesTechnical description
Outdoor sensor error
What causes this fault?
This fault occurs when the boiler loses communication with the small sensor unit located on the outside of your property. The most common reasons are either moisture causing a short circuit in the sensor's internal components or physical damage to the thin electrical cabling that runs through your exterior wall.
This fault is more common during autumn and winter, as heavy rain or freezing conditions can expose pre-existing cracks in the sensor housing or wiring.
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 →