Samsung Heat Pump Error Code E516

E516 indicates an open or short circuit fault in the equal oil temperature sensor circuit, located in the outdoor unit. The control board is receiving a signal from the sensor that falls outside the acceptable range, either no signal at all or a shorted reading. The system generates this error to protect the compressor from operating without valid oil temperature data.

Running the system with an active E516 error is not recommended. The oil temperature sensor monitors conditions that protect the compressor, and operating without valid sensor data could lead to compressor damage. The system may already be limiting or refusing to operate as a protective measure.

Repair costs depend on the underlying cause. If only a connector needs to be reseated, a service call fee in the range of $75 to $150 may be the only expense. If the oil temperature sensor requires replacement, parts and labor typically range from $150 to $400. PCB replacement, the least common outcome, can range from $400 to $900 or more depending on the unit model and labor rates in your area.

The first step, checking whether the sensor connector has come loose from the PCB, can be done by a mechanically confident homeowner after powering down the unit. However, measuring sensor resistance accurately requires a multimeter and knowledge of expected resistance values for that sensor, which is better suited to a qualified technician. If the sensor or PCB needs replacement, a licensed HVAC technician should perform the work.

A power reset may temporarily clear the error code, but if the underlying sensor fault, such as a disconnected connector, broken sensor, or damaged wire, is still present, E516 will return once the system restarts and the PCB polls the sensor again. The root cause must be identified and corrected for the error to clear permanently.