14th Oct 2026
Norcold N6XX / N8XX Flashing Temperature Setting (Thermistor Fault)
FLASHING TEMP
Norcold N6XX / N8XX Flashing Temperature Setting (Thermistor Fault)
The controls can’t read the thermistor, the temperature sensor clipped to the cooling fins. The fridge switches to its Backup Operating System and keeps cooling on a timer, but you have to set the temperature by hand until the thermistor is fixed.
Before you start
- Where it is. The thermistor is clipped to the 10th fin inside the fresh food compartment. Its wires share a connector with the compartment light.
- How backup mode works. The fridge runs the heat source on a timed cycle. A higher number on the TEMP button gives a longer cycle and colder fridge; a lower number gives a shorter cycle and warmer fridge.
- You’ll need a multimeter set to ohms (kilohms) and a glass of ice water.
Fits these models
Includes 2-way and 3-way versions, plus the .3 and IM (ice maker) versions.
What you’ll see on your model
N61X / N81X (LED lights)
N62X / N82X (one-letter display)
N64X / N84X (two-part display)
STEP 1
Check the wiring
Make sure the lamp/thermistor assembly is plugged into the wire harness. Check the wires and connector for dirty or broken connections.
Are the wires and connector good?
Clean or repair the connection
Clean or repair the terminals and connector, then turn the fridge off and back on.
STEP 2
Measure the thermistor
Unplug the thermistor and pack it in an ice bath for several minutes. Measure resistance across its two wires. Compare to Norcold’s chart:
| Temperature | Resistance |
|---|---|
| 32°F | 30.0–32.0 kΩ |
| 35°F | 24.5–25.5 kΩ |
| 40°F | 22.5–23.5 kΩ |
| 50°F | 15.5–16.5 kΩ |
| 60°F | 12.1–13.0 kΩ |
| 70°F | 11.1–12.0 kΩ |
| 75°F | 10.1–11.0 kΩ |
Is it about 30 to 32 kΩ at 32°F (or matches the chart)?
Replace the thermistor
The thermistor is open, shorted or out of range.
Norcold Thermistor 621742 →Norcold thermistor. Confirm it matches your old part number.Check the harness, then the board
The thermistor is good. Check the wire harness between it and the board for a break. If the harness is good, the board isn’t reading the sensor. ask a tech before you replace parts.
Still stuck? ask a tech with your model, serial number and the readings you got. We’ll confirm the part before you order.
Covers the Norcold N61X, N62X, N64X, N81X, N82X and N84X families. Based on the Norcold N6XX/N8XX service manual (publication 619394E), Thermistor Failure Fault / Backup Operating System flowchart.