Viking Freezer Error Code oPn

The oPn code means the control board detected an open circuit in the freezer thermistor within 15 seconds of powering on. The thermistor is the temperature sensor that feeds cabinet temperature data to the LV control board. Because the board cannot read a valid resistance value from the sensor, it flags the fault. The freezer continues to run the cooling system continuously to compensate, except during defrost cycles.

In most cases, yes. The oPn fault triggers a failsafe mode where the compressor runs continuously except during defrost, so the freezer should maintain cold temperatures. However, without a functioning thermistor, the unit cannot regulate temperature precisely, which could lead to temperature swings over time. It is a good idea to monitor the cabinet temperature with an independent thermometer until the fault is resolved.

A power reset may temporarily clear the oPn code from the display, but if the underlying fault, such as a failed thermistor or broken wire, is still present, the controller will detect the open circuit again within 15 seconds of powering back on and re-trigger the fault. A reset alone is not a fix. The thermistor circuit must be inspected, tested against the thermistor chart, and any failed component repaired or replaced before the code will stay clear.

A knowledgeable DIYer can perform the initial diagnostic steps, including visually inspecting the thermistor wiring, checking for loose connectors, and measuring thermistor resistance against the thermistor chart on Page 11. If the thermistor itself has failed, replacing it is a relatively straightforward repair involving disconnecting the harness and installing a new sensor. However, if the LV board is suspected, board replacement is best handled by a qualified technician.

Repair costs depend on what has failed. If the issue is only a loose or corroded connector, the repair may involve only a service call fee, which typically ranges from $75 to $150. A thermistor replacement part generally costs between $20 and $60, plus labor. If the LV control board requires replacement, total costs including parts and labor can range from $200 to $500 or more depending on the specific model.