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Error code reference

Maytag Refrigerator Error Code OP

Open thermistor detected on the corresponding thermistor circuit (fresh food, freezer, or machine compartment).

Maytag codesMaytag refrigerator codes
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What the OP error code actually means

Your Maytag refrigerator is displaying OP because one of its internal temperature sensors has stopped sending a readable signal to the control board. This sensor, called a thermistor, is responsible for monitoring temperatures so the fridge can cool properly. When the control board gets no signal or a signal that is completely out of range, it flags the OP code to let you know the sensor needs to be checked or replaced.

Diagnostic procedure

The full OP procedure

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1
First diagnostic step
Use Service Test 141, 142, or 143 to identify which thermistor is open; check thermistor resistance values.
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Most common causes of OP

Ranked by how often they cause this code
  1. 1Failed thermistor with open resistance
  2. 2Broken or damaged wiring in thermistor harness
  3. 3Loose or corroded connector at thermistor or control board
  4. 4Faulty main control board

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Questions people ask about OP

What does the OP error code mean on a Maytag refrigerator?
The OP code means the control board has detected an open thermistor or open circuit in one of the refrigerator's temperature sensor circuits. The thermistor is a small resistor that monitors compartment or evaporator temperatures. When the board reads no valid resistance from this sensor, it triggers OP to indicate it cannot get accurate temperature data.
Is it safe to use my Maytag refrigerator while the OP code is displayed?
Short-term use may be possible but is not advisable for extended periods. Without a functioning thermistor, the control board cannot accurately regulate temperatures, which means food safety is at risk if cooling becomes erratic or stops. Monitor actual compartment temperatures with a separate thermometer and transfer perishables if temperatures rise above 40 degrees Fahrenheit in the fresh food section or above 0 degrees in the freezer.
Can a loose wire cause the OP code on a Maytag refrigerator?
Yes, a loose or unseated connector in the thermistor circuit will create an open circuit that triggers the OP code even if the thermistor itself is functioning correctly. Before ordering a replacement sensor, reseat all connectors in the thermistor wiring harness at both the sensor end and the control board end, then clear the code and test the unit.
How do I fix the OP error code on my Maytag refrigerator?
Start by running the refrigerator's service test mode to identify which thermistor circuit is reporting open. Then check the resistance of that thermistor using a multimeter and compare it against the manufacturer's spec for the current temperature. Also inspect the wiring harness and connectors for breaks, corrosion, or loose connections. If the thermistor reads as open or infinite resistance, replace the sensor. If wiring is damaged, repair or replace the harness.
How much does it cost to fix the OP error code on a Maytag refrigerator?
A replacement thermistor typically costs between $15 and $50 depending on which sensor is affected and the model. If you are comfortable using a multimeter and doing basic appliance repair, this is a low-difficulty DIY repair. Professional labor adds roughly $100 to $200 for diagnosis and replacement. If the wiring harness needs repair or replacement, parts and labor can push the total higher.

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