Originally Posted by Elcam84 (Post 30735)

Typically 10-15 years. Pretty much the same as a central unit.

As long as the coils don't leak and compressor keeps running it takes little to maintain. Some places have stuff int he air that can accelerate corrosion of coils and some houses do as well. Doing refrigeration the biggest killer of coils was chicken. Raw chicken puts off a mild acid that eats away at evap coils. They have sprayers that wash the coils off to make them last longer. The number of times the compressor cycles has a big impact as well.
The most common failure I have seen in minisplits is the powersupply on inverter units. The single speed ones are more reliable because they don't have a big supply putting out 380Vdc with big capacitors in a hot condenser. The big caps are easy to get and an easy repair though and worth the hassle over a single speed.