How often do heat pumps need to be cleaned/maintained?

The condenser (outside unit) should be professionally cleaned once a year, and the filter in the head (inside unit) should be cleaned every few months. The inside filters are easy to check for dust and clean (sort of like a vacuum filter!).  Interior mini-splits should also be professionally cleaned from time to time, and we would recommend discussing this with your heating and cooling contractor when they are on site to service the condenser annually.