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Error code reference

Amana Dryer Error Code oP

Thermistor is open or temperature near the thermistor has fallen below 30°F, causing the control to display…

Amana codesAmana dryer codes

Thermistor is open or temperature near the thermistor has fallen below 30°F, causing the control to display an open circuit condition.

First step from the service manual

Disconnect electric power to dryer and remove front panel; check for broken, loose or incorrect wiring between thermistor and control.

The complete diagnostic procedure includes additional test steps, resistance specifications, wiring diagram references, and component test points.

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What oP means on a Amana dryer

The OP error code indicates the control board has detected an open circuit in the thermistor circuit, meaning the resistance reading is outside the expected range or has gone completely infinite. The thermistor is a temperature-sensing resistor mounted in the dryer's airflow path that continuously reports temperature data to the control board. When the board sees an open thermistor signal, it cannot confirm safe operating temperatures and triggers this fault. On some Amana control displays, this code appears as 'oF' rather than 'OP'. The code can also be triggered if the ambient temperature near the thermistor drops below 10°F, which pushes the resistance reading outside the board's acceptable window.

For homeowners, the thermistor is a small sensor that tells your dryer how hot the air inside is getting. If this sensor stops sending a readable signal, your dryer shuts down rather than risk overheating or running blind without temperature feedback. The most common reasons for this error are a broken wire leading to the sensor, a loose connector, or the sensor itself having failed. Cold weather can occasionally trigger a false OP code if your dryer is installed in an unheated garage or space that drops below 10°F. Before replacing any parts, a wiring inspection is always the first step.

Source: manufacturer service documentation.

Common causes of oP

  1. 01

    Broken or disconnected wiring between thermistor and control board

    Wiring / connection

    A wire in the harness running from the thermistor to the control board may have broken, burned, or pulled loose from its connector, creating an open circuit. This is the most common trigger for this code and is why the first troubleshooting step targets wiring inspection.

  2. 02

    Failed thermistor

    Part replacement

    The thermistor itself can fail internally, causing its resistance to read as infinite (open) to the control board. A resistance measurement across the thermistor terminals will confirm this; a functioning thermistor reads within a predictable range at room temperature, typically around 10,000 ohms at 77°F.

  3. 03

    Ambient temperature below 10°F near the thermistor

    Wiring / connection

    Extremely cold installation environments, such as an unheated garage in winter, can push the thermistor's resistance reading so high that the control board interprets it as an open circuit and displays OP or oF. Warming the laundry space above 10°F and power-cycling the dryer will clear this if cold temperature is the cause.

  4. 04

    Faulty control board

    Part replacement

    If the wiring and thermistor both test within spec, the control board's thermistor input circuit may have failed, causing it to incorrectly report an open reading. This is the least common cause and should only be considered after all wiring and the thermistor itself have been verified.

See the test procedure for each cause

Frequently asked questions about oP

What does the OP error code mean on an Amana dryer?
The OP code means the control board is detecting an open circuit in the thermistor, the temperature sensor inside the dryer. This can be caused by a broken or loose wire in the thermistor circuit, a failed thermistor, or ambient temperatures dropping below 10°F near the sensor. On some Amana controls, this same fault displays as 'oF' instead of 'OP'.
Is it safe to use my Amana dryer while the OP code is showing?
You should not continue running the dryer with an active OP code. The thermistor is the primary temperature sensor the control board uses to prevent overheating. Without a valid temperature reading, the dryer cannot regulate heat safely, which creates a potential fire hazard. Stop using the dryer until the fault is diagnosed and resolved.
How do I fix the OP error code on my Amana dryer?
Start by disconnecting power to the dryer, then remove the front panel to access the thermistor wiring. Inspect all wires and connectors between the thermistor and the control board for breaks, burns, or loose terminals. If wiring looks intact, use a multimeter to measure resistance across the thermistor terminals; if the reading is infinite or far outside the expected range (around 10,000 ohms at room temperature), replace the thermistor. If both the wiring and thermistor check out, the control board may need replacement.
How much does it cost to fix an OP error on an Amana dryer?
If the fix is just reseating a loose connector, there is no parts cost, only your time. A replacement thermistor for an Amana dryer typically costs between $10 and $30 for the part. A control board is significantly more expensive, ranging from $100 to $250 or more depending on the model. If you hire a technician, expect a diagnostic fee plus labor, which usually runs $80 to $150 on top of parts costs.
Can cold weather cause the OP code on an Amana dryer?
Yes. If the temperature near the thermistor drops below 10°F, the sensor's resistance rises to a level the control board reads as an open circuit, triggering the OP or oF code. This is common in unheated garages during winter. Move the dryer to a warmer location or heat the space above 10°F, then restore power to see if the code clears on its own before assuming a component has failed.

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