Frigidaire Refrigerator Error Code OP

The OP code means the control board is detecting an open circuit on the freezer thermistor. The thermistor is the temperature sensor inside the freezer compartment, and an open circuit means the board is receiving no signal from it at all. This typically points to a failed thermistor, a loose wiring connector, or a broken wire in the sensor circuit.

Short-term use is possible, but the risk increases the longer the problem goes unresolved. Without a functioning freezer thermistor, the control board cannot accurately regulate freezer temperature, which may cause food to partially thaw or the compressor to run continuously. Place a standalone thermometer in the freezer to monitor actual temperature and avoid storing temperature-sensitive items until the sensor is repaired.

Frigidaire uses the blank fresh food display as part of the diagnostic presentation for the OP code. When the freezer thermistor circuit is open, the control board displays OP on the freezer side and leaves the fresh food display blank to signal that the fault is specific to the freezer sensor. This display behavior is normal for this code and is not a sign of a separate fresh food section problem.

Start by locating the freezer thermistor, which is usually clipped to the evaporator cover or sidewall inside the freezer. Check that its wiring connector is fully seated and undamaged. Use a multimeter to test the thermistor's resistance at room temperature, comparing the reading to the manufacturer's spec. If the thermistor reads open or infinite resistance, replace it. If the thermistor and wiring check out, the control board may need replacement.

A replacement freezer thermistor is typically an inexpensive part, often in the $10 to $30 range for most Frigidaire models. If the fix is only a loose connector, there is no parts cost at all. Labor from a technician usually adds $75 to $150 depending on your area. If the control board turns out to be the cause, board replacement can cost $100 to $300 or more for the part alone, making professional diagnosis worthwhile before purchasing a board.