The short answer
Most mini-split smells and airflow loss come from dirty filters and a coated coil and blower wheel. Rinse the washable filters every few weeks in season; once a year, wash the coil and blower with a cleaning bag that catches the runoff and an evaporator-safe cleaner.
Steps
- Switch off power at the breaker.
- Open the front panel and rinse the filters in lukewarm water; let them dry.
- Hang a cleaning bag under the head; Leak Saver's kits come in sizes for different head widths.
- Spray a no-rinse evaporator coil cleaner such as DiversiTech's on the coil, then rinse the coil and blower with a pump sprayer.
- Let everything dry for several hours before restoring power.
Outdoor unit
Hose the outdoor coil gently from inside out, keep 2 ft clear around it, and clear leaves and snow from the base.
SafetyKeep water away from the control board and display, and call a technician if the blower wheel needs removing.
Products mentioned
Questions readers ask
How often should a mini-split be cleaned?
Filters every few weeks in season; a full coil and blower wash once a year, more often with pets or dust.
Why does my mini-split smell?
Usually biofilm on the coil and blower wheel; a deep clean with a coil cleaner and bag kit removes it.