BoilerFaultCodesTechnical description
Outside temperature is adopted by the LON BUS
What causes this fault?
This occurs because your boiler has detected that it is receiving outdoor temperature data from another device on your home network rather than from its own dedicated sensor. It typically happens when the boiler is linked to a wider building management system or a smart home network that takes over the job of telling the boiler how cold it is outside. This isn't a mechanical breakdown, but rather a change in how the boiler's computer is communicating with other parts of your home.
DIY fix possible
Check if any other connected heating controls or smart home devices have been recently updated or restartedPress the 'Reset' button on the boiler control panelMonitor the boiler display; if your heating is working normally, no further action is required