Samsung Heat Pump Error Code E512

E512 indicates a discharge temperature sensor error on the second constant speed compressor. The control board has detected either an open circuit or a short circuit in the sensor circuit, meaning the signal is outside the valid resistance range. The system triggers this fault to prevent the compressor from running without proper thermal monitoring.

It is not advisable to continue operating the unit with an active E512 fault. The discharge temperature sensor protects the second constant speed compressor from thermal damage, and running the system without reliable temperature monitoring risks a compressor failure. Power down the unit until the fault is diagnosed and resolved.

A power reset may temporarily clear the fault code, but if the underlying sensor or wiring issue remains, E512 will return once the system restarts and the PCB re-evaluates the sensor circuit. A reset alone is not a fix. The sensor connector should be inspected and resistance measured to confirm the circuit is functioning correctly before returning the unit to normal operation.

The first diagnostic step, checking whether the sensor connector is seated properly at the PCB, is something a knowledgeable DIYer can attempt after safely powering down the unit. However, measuring sensor resistance, tracing wiring faults, and replacing components inside a heat pump refrigerant system typically requires a qualified HVAC technician. If the connector appears secure and the error persists, professional service is recommended.

Repair costs depend on the root cause. Reconnecting a loose connector involves only a service call fee, typically in the range of $75 to $150. Replacing a discharge temperature sensor usually costs $100 to $300 including parts and labor. If the control PCB requires replacement, costs can rise to $400 to $800 or more depending on the model and parts availability.