Whirlpool Refrigerator Error Code OP

The OP code means the control board has detected an open circuit in a thermistor or temperature sensor circuit. It appears when the sensor's resistance reading falls below the defined COLD limit, which signals a broken electrical path rather than a valid temperature reading. This prevents the refrigerator from accurately monitoring and controlling its internal temperatures. The fault is most often traced to a loose connector, broken wire, or a failed thermistor.

Continued use is risky because the control board cannot reliably regulate cooling without a functioning temperature sensor. Food temperatures may drift outside safe ranges without any visible indication. It is best to check and transfer perishable items to another cooler or refrigerator until the fault is diagnosed and repaired.

A power reset may temporarily clear the code from the display, but the OP code will return if the underlying open circuit condition still exists. The control board will detect the faulty sensor reading again once it resumes normal operation. A reset is useful for confirming whether the fault is intermittent, but it is not a repair. The thermistor wiring and sensor must be physically inspected and tested to resolve the fault.

Start by inspecting all thermistor wire harness connectors for loose or disconnected plugs and reseat any that are not fully engaged. Then use a multimeter to measure the resistance of the thermistor itself. If the meter reads infinite resistance at any temperature, the thermistor has an internal open and needs to be replaced. If the thermistor tests correctly, inspect the full wire run for breaks or corrosion before suspecting the control board.

If the fix is simply reseating a loose connector, there is no parts cost involved. A replacement thermistor typically costs between $10 and $40 depending on the specific sensor and model. If the wiring harness needs to be replaced, parts can range from $20 to $80. Adding professional labor, total repair costs generally fall between $75 and $200 for sensor or wiring related repairs.