OWNER ANSWER
ATTO 2: musty smell from the air conditioning
For a damp, musty smell when the ATTO 2 air conditioning starts, BYD recommends fresh-air ventilation before parking and regular cabin-filter inspection. Moisture left on the evaporator can contribute to odour. Persistent smell needs an inspection rather than repeated deodorising.
ATTO 2 electric, RHD July 2025 EN_V1. Controls and equipment must match your car.
- Check that the air intake in front of the windscreen is clear of leaves and other loose debris. Keep the cabin clean and the space under the front seats clear.
- Before parking, switch off A/C cooling and leave the fan providing fresh outside air. Use ventilation rather than recirculation for this drying step; the handbook gives no fixed duration. Safety note: Keep the windscreen clear; restore demisting if it starts to mist. Smoke or a burning smell needs a different fault response, not this odour-prevention routine.
- Check when the cabin filter was last inspected or replaced and arrange an inspection if it is due or its condition is unknown.
- On the next ordinary use, compare whether the smell has reduced, disappears quickly or continues throughout ventilation. The blower may run after switching off and locking to dry the evaporator; the handbook describes that behaviour as normal.
What success looks like
The musty smell reduces or no longer persists during ordinary ventilation. A fan running after locking can be part of drying; it is not by itself evidence of a fault or proof that an odour problem is cured.
If that did not work
If the smell persists after these measures, ask BYD to inspect the filter and climate system for the source of the odour. Explain whether it occurs only on first start or continues, and whether the filter was recently changed. If airflow or temperature is also wrong, use the separate ATTO 2 climate checks. The cited handbook does not prescribe chemical injection through a drain hose or a timed maximum-heat cycle.
Useful next steps
BYD ATTO 2 electric, RHD July 2025 EN_V1 handbook, PDF pages 150, 151. Checked 13 November 2026.
Open source (BYD UK)