Keeping a Ductless Mini-Split Clean Between Visits

Ductless mini-splits are low maintenance, but not no maintenance. A few habits between professional cleanings keep them efficient and odor free.

Rinse the filters every few weeks

Lift the front panel and slide out the mesh filters. Rinse them under lukewarm water, let them dry completely and slide them back in. In heavy use or with pets, every two to four weeks is about right.

Watch the vanes and outlet

Look into the outlet with a flashlight. Black spots on the vanes or the blower wheel mean mold is growing. That calls for a deep cleaning, since the blower wheel cannot be reached without partial disassembly.

Use dry mode on humid days

Many mini-splits have a dry or dehumidify mode. On mild humid days, it pulls moisture without overcooling, which also keeps the inside of the unit from staying damp.

Keep the outdoor unit clear

Clear leaves, grass clippings and snow from around the outdoor unit. In winter, make sure it sits above snow level and that defrost water can drain away.

When to call

• Water dripping from the indoor unit.
• A musty smell at startup that does not fade.
• Weak airflow even with clean filters.
• Error lights or codes on the indoor unit.

A yearly deep cleaning, combined with regular filter rinses, keeps most mini-splits running quietly and efficiently for many years.