Best Practices and Troubleshooting Tips for Ductless Mini Splits

May 14, 2015

Although ductless mini splits provide years of dependable operation, they do require upkeep and occasional troubleshooting. All air conditioners and heat pumps, including the mini split,require periodic attention. Mini splits use the same components that central cooling systems do, minus the ductwork, and perform better and more durably when they're dust-free and operating within the manufacturer's tolerances.

Maintenance Tips

  • Keeping the mini split clean not only improves its energy efficiency, but it also increases its durability. The air filter inside the indoor air handler needs to be cleaned or replaced whenever it's coated with dust. Dust is the most harmful environmental factor mini splits encounter because it acts as insulation, keeping the parts warmer, which keeps them from performing optimally.
  • A dust-covered air filter also slows the air flowing through the air handler, and may cause the evaporator coil to freeze over, damaging the compressor in the outdoor condenser.
  • Allowing excessive dust to build on and inside the outdoor condenser can harm your system. Gently hose it off periodically, and clean the condensing coil with a soft brush. Keep vegetation and other objects away from the condenser and try to avoid scattering grass clippings on the coil with the lawnmower. Never place anything on top of the condenser.
  • Occasionally check the condensate drain pipe for adequate drainage. You may need to clear the end of the drainpipe periodically.


  • If the evaporator coil and air filter are clean and the system freezes over, you may need an HVAC pro to check the refrigerant level. Refrigerant leaks in ductless mini splits are rare but can occur, and low refrigerant levels will make the coil freeze.
  • If the remote stops working, press the reset button and check the batteries. When neither of these solutions work, contact the manufacturer. You may need to replace the remote.
  • The mini split may not perform up to your expectations during weather extremes. Check the owner's manual to learn its temperature limits.
For more information about using ductless mini splits, contact Lozier Heating and Cooling. We've been providing HVAC services for the Des Moines area homeowners since 1906. Our goal is to help educate our customers in the greater Des Moines, Iowa area about energy and home comfort issues (specific to HVAC systems). Credit/Copyright Attribution: "docstockmedia/Shutterstock"