Maytag · Refrigerator Moderate

OP — Open Thermistor (Service Diagnostics)

OP is a service-diagnostic display code, not a door-ajar alarm. In the refrigerator's built-in service/diagnostic test mode, OP appears in place of a temperature reading when a thermistor (fresh food, freezer, ambient, or ice box sensor, depending on the test number) has an open circuit. OP is also used in the door-switch tests to indicate a door reading as open. (SH means a shorted thermistor.) You normally only see OP after entering the refrigerator's diagnostic mode — check your model's tech sheet for the exact test-number sequence.

Keep using it?
Yes, with caution
DIY difficulty
Moderate

How to fix it

  1. Confirm you're seeing OP during the refrigerator's built-in service/diagnostic mode, not as a normal-use alert — the everyday door-ajar chime/icon is a separate, unrelated indicator.
  2. Identify which test number displayed OP (per your model's tech sheet) to know whether it's a thermistor test (fresh food/freezer/ambient/ice box) or a door-switch test.
  3. For a thermistor test: unplug the refrigerator, locate that sensor, and check its wiring connector for a secure connection.
  4. Measure the thermistor's resistance with a multimeter — an open (infinite/OL) reading confirms a failed sensor; replace it.
  5. For a door-switch test showing OP: inspect that door's switch and door alignment/gasket instead — this is not a sensor issue.

Why it happens

Typical signs: 'OP' shown while running the refrigerator's built-in service/diagnostic test (not during normal use) · Fresh food, freezer, or ice box compartment temperature reads incorrectly or won't display in diagnostics · Possible erratic cooling or temperature control if the affected thermistor feeds compressor/damper control

  • Open (failed) thermistor The fresh food, freezer, ambient, or ice-box thermistor circuit is open — a broken sensor element or a disconnected/cut wire.
  • Disconnected thermistor connector The plug at the sensor or at the control board has come loose.
  • OP shown during a door-switch test In the door-switch portion of diagnostics (not a thermistor test), OP indicates the tested door is reading as open — check that switch and door alignment instead of a sensor.

Replace your water filter

A clogged or overdue water filter is a common cause of low water and ice flow on Maytag refrigerators — they are meant to be changed about every 6 months. The OEM-style filter that fits most Maytag refrigerators is the EDR1RXD1 ($40-50 OEM, $15-25 compatible).

  • Whirlpool EDR1RXD1 refrigerator water filter OEM water filter
    Amazon →

Not sure which filter fits your model? See the full compatibility guide →

Parts you may need

If diagnosis points to a failed part, these are the common replacements. As an Amazon Associate we earn from qualifying purchases.

  • Maytag refrigerator thermistor (temperature sensor — confirm fresh food / freezer / ice box per your model) Common replacement
    Amazon →

More Maytag refrigerator codes

CF CF — Communication Failure (UI to Main) F4E1 F4E1 — Defrost-System Fault F8E1 F8E1 — Temperature-Sensor / Ice-System Fault Ic "Ic" — Ice Status Indicator (Not a Fault) PO PO — Power Outage Alert

All Maytag codes → All refrigerator codes →

Frequently asked questions

What does the OP code mean on a Maytag refrigerator?

OP is a service-diagnostic display code, not a door-ajar alarm. In the refrigerator's built-in service/diagnostic test mode, OP appears in place of a temperature reading when a thermistor (fresh food, freezer, ambient, or ice box sensor, depending on the test number) has an open circuit. OP is also used in the door-switch tests to indicate a door reading as open. (SH means a shorted thermistor.) You normally only see OP after entering the refrigerator's diagnostic mode — check your model's tech sheet for the exact test-number sequence.

What causes the OP code on a Maytag refrigerator?

Open (failed) thermistor: The fresh food, freezer, ambient, or ice-box thermistor circuit is open — a broken sensor element or a disconnected/cut wire. Disconnected thermistor connector: The plug at the sensor or at the control board has come loose. OP shown during a door-switch test: In the door-switch portion of diagnostics (not a thermistor test), OP indicates the tested door is reading as open — check that switch and door alignment instead of a sensor.

Is it safe to keep using a Maytag refrigerator with a OP error?

Yes, with caution. This is rated a moderate-severity fault.

How do I fix OP on a Maytag refrigerator?

Confirm you're seeing OP during the refrigerator's built-in service/diagnostic mode, not as a normal-use alert — the everyday door-ajar chime/icon is a separate, unrelated indicator. Identify which test number displayed OP (per your model's tech sheet) to know whether it's a thermistor test (fresh food/freezer/ambient/ice box) or a door-switch test. For a thermistor test: unplug the refrigerator, locate that sensor, and check its wiring connector for a secure connection.

Always unplug an appliance before servicing it. This guide is for informational purposes and is not a substitute for a qualified technician.