Amana Refrigerator Error Code Open Thermistor

It means the control board has detected a break in the circuit connecting one of the temperature sensors (thermistors) in the freezer or refrigerator compartment. Without a functioning thermistor signal, the board cannot monitor or regulate the internal temperature properly. The indicator lights 4 through 7 will sequence as a visual alert until ALARM OFF is pressed. The fault can be caused by a bad thermistor, damaged wiring, or a failed L.V. control board.

Pressing ALARM OFF will silence the visual alarm (the sequencing indicator lights), but it will not clear the underlying fault. The error will return as long as the thermistor circuit remains open. The root cause, whether a failed sensor, a wiring fault, or a board issue, must be repaired before the error will stop recurring.

Repair costs vary depending on which component has failed. A replacement thermistor sensor is typically the least expensive fix, with parts generally ranging from $15 to $50. If the wiring harness requires repair or replacement, costs can range from $30 to $100 for parts. An L.V. control board replacement is the most expensive scenario, with parts typically ranging from $80 to $250, plus any labor charges if a technician performs the repair.

Start by pressing ALARM OFF to silence the indicator lights, then check the thermistor resistance with a multimeter at the sensor connector. If resistance reads infinite or out of range, the thermistor needs replacement. If the sensor tests correctly, inspect the wiring harness between the thermistor and the L.V. board for breaks, loose connections, or corrosion and repair as needed. If both the sensor and wiring are intact, the L.V. control board may require replacement.

Continued use carries some risk, because the control board cannot accurately monitor internal temperatures without a working thermistor. The refrigerator may not cool properly, which could allow food to warm to unsafe temperatures. It is advisable to check food temperatures with a standalone thermometer and address the repair as soon as possible rather than relying on the appliance to maintain safe conditions.