AC air handler squealing or grinding noises. Though most air handlers have direct-drive motors, some older units may be belt-driven. Squealing sounds from a belt-drive air handler generally occur when the belt that connects the motor to the blower slips. In most cases, the belt is improperly aligned or worn and needs replacement. Follow the instructions above under Air Conditioner Not Blowing Air and refer to your owner’s manual.
7) Schedule an annual tune-up with an HVAC professional. A trained HVAC technician can detect most problems before they become major ones. With a cost of around $100 for a routine maintenance call, the benefits will likely outweigh the costs by a considerable margin. A typical tune-up will include various tests to ensure your unit’s internal parts are functioning correctly, as well as a filter check, and a refrigerant charge if needed. Your technician will likely also clear the drain, and clean your unit thoroughly inside and out.