Samsung Air Conditioner Error Code E602

The Samsung E602 error code indicates a second-stage detection of the floating switch in the indoor unit drain pump circuit. This means the system has detected a persistent elevated water level in the drain plate that was not resolved after the initial (first) detection event. The floating switch is a safety device positioned in the condensate drain pan. When condensate water rises above an acceptable level, the float rises and triggers the switch, signaling the control board to shut down or restrict operation to prevent water overflow and potential water damage.

The E602 designation specifically marks this as a secondary or confirmed detection, meaning the unit had already registered a drainage concern and the water level did not return to normal within the expected window. This persistent condition points to a genuine blockage, pump failure, or float switch fault rather than a momentary spike in condensate production. This code is most commonly associated with cassette-type indoor units, which rely on an integrated drain pump to lift condensate water out of the unit and into a drain line.

The recommended first diagnostic step involves confirming whether the indoor unit is a cassette type and then measuring the resistance across the float switch connector. A faulty float switch may read an open circuit or out-of-range resistance even when the drain pan is dry, causing a false persistent fault. If resistance values are within specification, attention shifts to the drain pump itself, the condensate drain line for blockages, and the drain pan for debris or algae buildup that could impede proper drainage.