Samsung Air Conditioner Error Code E277

Error code E277 on a Samsung air conditioner indicates a fault detected at the top sensor of compressor 2. This sensor is a thermistor responsible for monitoring the discharge temperature at the top of the second compressor in a multi-compressor system. The error triggers when the unit's control board reads a signal from this thermistor that falls outside the expected resistance range, indicating either a short circuit (resistance too low) or an open circuit (resistance too high or infinite). Both conditions prevent accurate temperature monitoring and cause the system to shut down as a protective measure.

The first step in diagnosing E277 is to inspect the sensor connector and measure the thermistor's resistance with a multimeter. A properly functioning thermistor will produce a resistance reading that correlates with the ambient or compressor temperature at the time of measurement. A short will typically read near zero ohms, while an open circuit will read out of range or show no continuity at all. Connector issues such as corrosion, bent pins, or a loose plug can also produce intermittent or false readings that trigger this code.

Common root causes include a failed thermistor due to heat exposure or age, wiring harness damage between the sensor and control board, and connector degradation from moisture or vibration. Because compressor 2 operates under high heat and mechanical stress, sensors in this location are more prone to failure over time. If the connector and wiring check out, the thermistor itself will likely need to be replaced to resolve the fault.