Mini-Split Troubleshooting
Communication errors, thermistors and inverter boards.
Mini-Split Not Cooling or Heating: A Diagnostic Order for Ductless Systems
How to troubleshoot a ductless mini-split that runs but won't cool or heat: error codes, mode and remote settings, filters and blower wheels, the outdoor unit, sensors, communication and charge.
How to Test a Mini-Split Thermistor (Temperature Sensor)
Test a mini-split room, coil, discharge or outdoor temperature sensor with an ohmmeter and the manufacturer's resistance table, and find out whether the sensor, wiring or board is bad.
Mini-Split Communication Errors: How to Troubleshoot Indoor-to-Outdoor Faults
A step-by-step approach to mini-split communication faults between the indoor and outdoor units, covering wiring, polarity, voltage and boards.
Working Safely on Mini-Split Inverter Boards
Why mini-split inverter boards stay dangerous after power-off, how to verify the DC bus is discharged, and how to approach IPM, voltage and compressor drive error codes.