A ductless mini-split is a heat pump, so plan on 10 to 15 years, with 20 possible for a lightly used unit that is cleaned regularly.
A mini-split moves refrigerant between a small outdoor compressor and one or more wall-mounted indoor heads. Nearly all of them are inverter-driven, which means the compressor runs at variable speed instead of switching on and off. That is gentle on the parts, and makers and installers often quote 15 to 20 years. Independent ranges for heat pumps in general are 10 to 15.
The parts that fail are the outdoor fan motor, the control boards, and the indoor blower wheel when it gets caked with dust and mold. Refrigerant leaks at the flare fittings are the common installation fault and show up as weak heating or cooling.
Mini-split makers often do not put the date in the serial number, so the plate's printed manufacture date, or the installer's invoice, may be the only record.
Find the serial number and decode it: Daikin · Mitsubishi Electric · LG · Fujitsu · Gree · Bosch (heat pumps and geothermal)
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