Samsung Heat Pump Error Code E558

E558 is a suction temperature sensor breakaway fault. The heat pump monitors the difference between the suction line temperature recorded at compressor startup and the current suction line temperature. If that difference stays below 2°C for 30 continuous minutes, the system triggers E558 because it concludes the sensor is no longer properly tracking refrigerant temperature changes. The most common cause is the sensor coming loose from its mounting holder on the suction pipe.

Operating the heat pump with E558 active is not recommended. The suction temperature sensor is used by the control system to protect the compressor and regulate refrigerant flow. Running the unit without a reliable suction temperature reading could allow the compressor to operate outside safe parameters, potentially causing compressor damage over time. The system should be diagnosed and repaired before resuming normal use.

If the repair is simply reseating a dislodged sensor in its holder, the cost may be limited to a service call fee, typically in the range of $75 to $150. If the NTC thermistor sensor requires replacement, parts and labor together generally fall in the $150 to $350 range depending on the specific unit and local labor rates. Control board replacement, if required, can push repair costs to $400 or more.

A basic visual inspection of the suction sensor and its mounting bracket is something a knowledgeable homeowner can do, and if the sensor is simply dislodged from its holder, reseating it may clear the fault. However, measuring NTC thermistor resistance, testing wiring harness continuity, and evaluating refrigerant charge levels require a multimeter and refrigeration certification respectively. If the sensor itself has failed or a refrigerant issue is involved, a qualified technician should complete the repair.

A power reset may temporarily clear the fault display, but E558 will return if the underlying issue with the suction sensor is not corrected. Because the fault requires 30 minutes of compressor operation with less than 2°C temperature differential to trigger, the error will reappear once the system runs through that detection cycle again. A physical inspection and sensor resistance check are necessary to resolve the fault permanently.