DIAGNOSIS
The machine is stuck on a filter life alert. This is a known firmware glitch after a filter change, not a sensor issue.
FIX
1. Unplug the machine from the wall for 60 seconds.
2. Plug it back in and wait for the boot sequence.
3. Hold the 'Oscillation' and 'Night Mode' buttons simultaneously for 5 seconds. The display should flash.
4. The filter life indicator should now show full bars.
IF THAT DIDN'T WORK
Perform a full factory reset via the Dyson Link app. Navigate to the machine settings and select 'Reset to factory settings'. This clears all stored data, including the erroneous filter timer.
HEADS UP
The filter reset command only works when the machine is in standby mode, not while it's actively heating or cooling.