The low-pressure switch is designed to turn the system off if the refrigerant pressure drops below a certain level. This is often a sign of a major leak or a failure in the Expansion Valve. By shutting down the unit, the switch prevents the compressor from running "dry" and burning out. This is a standard protection feature on our Professional Grade systems. If your Ductless Mini Split stops cooling and throws a code, this switch may have been triggered. We provide technical support and Parts to help you get back up and running. It is a vital part of our Warranty Policy that these safety features remain operational. You can find more information on leak detection in our Help section.