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Error code reference

Norcold Refrigerator Error Code oP LI

The temperature monitor control (TMC) limit switch is open or not connected to power board terminals LIMIT IN and LIMIT OUT, stopping AC and gas…

Norcold codesNorcold refrigerator codes
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What the oP LI error code actually means

Your Norcold refrigerator has detected a problem with a small safety device called the temperature monitor control, which watches for overheating inside the fridge's cooling system. Because this safety device is not communicating properly with the control board, the fridge has shut off both the electric and propane heating to protect itself. You will need to inspect this safety device and its wiring before the refrigerator will run again.

Diagnostic procedure

The full oP LI procedure

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1
First diagnostic step
Check if TMC red light is on solid or flashing, and follow the oP LI diagnostic flowchart.
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Most common causes of oP LI

Ranked by how often they cause this code
  1. 1Loose or disconnected TMC wiring at power board
  2. 2Tripped TMC limit switch due to overheating
  3. 3Failed TMC unit
  4. 4Damaged or broken wiring harness
  5. 5Corroded or faulty power board terminals

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Questions people ask about oP LI

What does oP LI mean on a Norcold refrigerator?
The oP LI code means the temperature monitor control (TMC) limit switch circuit is open, either because the switch itself has tripped or because the wiring between the TMC and the power board terminals LIMIT IN and LIMIT OUT is disconnected or faulty. When this fault is detected, the power board shuts down both AC and LP gas operation as a safety measure. The refrigerator will not cool until the fault is diagnosed and corrected.
Will resetting the refrigerator clear the oP LI error?
A simple reset will generally not permanently clear an oP LI code if the underlying cause has not been fixed. If the TMC limit switch is open due to a wiring fault or a failed component, the code will return immediately or shortly after power is restored. The fault in the TMC circuit or its wiring must be resolved first.
How much does it cost to repair an oP LI error on a Norcold refrigerator?
Repair costs depend on the root cause. If the issue is simply a loose connector at the power board, there may be no parts cost at all, only labor time. Replacing a failed TMC unit typically involves parts costs in the range of $30 to $80 or more depending on the model, plus any applicable labor charges. If the power board itself is damaged, costs can be significantly higher.
Is it safe to use my Norcold refrigerator when oP LI is displayed?
No, you should not attempt to bypass or continue operating the refrigerator while oP LI is active. The TMC is a thermal safety device that protects the unit from overheating, which can be a fire risk in absorption refrigerators. The power board has already shut off heating operation, so the fridge will not cool. Address the underlying fault before using the unit again.
How do I start diagnosing and fixing the oP LI error?
Start by checking the TMC red indicator light. A solid red light points toward a wiring or connection problem at the power board terminals LIMIT IN and LIMIT OUT, while a flashing red light suggests the TMC itself has tripped or failed. From there, follow the oP LI diagnostic flowchart for your specific Norcold model to work through each possible cause in sequence, checking wiring, connectors, and the TMC device itself.

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