Samsung Heat Pump Error Code E135

E135 indicates an error with the equal oil temperature sensor in the outdoor unit. The control board has detected either an open circuit or a short circuit from this sensor, meaning the reading is outside the acceptable range. This sensor monitors oil temperature to help protect the compressor. The system may restrict or halt operation until the fault is resolved.

Running the heat pump while this error is active is not recommended. The oil temperature sensor provides data the control system uses to protect the compressor from damage. Without a reliable sensor reading, the system cannot properly monitor oil conditions, which could lead to compressor wear or failure if operation continues.

A power reset may temporarily clear the error code, but if the underlying cause, such as a failed sensor, damaged wiring, or loose connector, has not been corrected, the E135 code will return once the system restarts and re-checks the sensor circuit. Always diagnose and correct the root cause before relying on a reset to restore normal operation.

The first step, checking and reconnecting the sensor connector on the outdoor unit PCB, is a straightforward task that a knowledgeable DIYer can perform after disconnecting power to the unit. However, if the sensor or wiring harness needs replacement, or if the PCB is suspected, a qualified HVAC technician should handle the repair to ensure correct diagnosis and safe handling of the refrigerant system components.

If the fix is simply reconnecting a loose sensor connector, there may be little to no parts cost beyond a service call, typically ranging from $75 to $150. Replacing the oil temperature sensor itself generally costs between $50 and $200 for the part, plus labor. If the PCB requires replacement, total repair costs can range from $300 to $800 or more depending on the model and labor rates in your area.