Dometic Portable Cooler: “Warning 01 / 02 (NTC sensor)”
warning Dometic cooler error codes
What it means
The cooler's temperature sensor (an NTC thermistor) reads as an open circuit (01) or a short circuit (02). The controller can no longer trust the temperature reading and flags a sensor fault. On dual-zone models this refers to the single-zone / large-compartment sensor.
Most likely causes
- Disconnected, broken, or pinched NTC sensor wire (open circuit, code 01) common
- Shorted NTC sensor or wiring, often from moisture/damage (short circuit, code 02) common
- Failed NTC thermistor common
- Internal control-board fault less common
Safe checks you can do yourself
- With power off, inspect any accessible sensor wiring and connectors for damage, looseness, or moisture.
- Make sure nothing inside the box is crushing or pinching the sensor lead.
- Note: the sensor is internal — confirm the fault by ruling out obvious external causes before seeking service.
How to reset / clear Warning 01 / 02 (NTC sensor)
- Switch off and disconnect power for at least 5 minutes, then power back on to see if it was a transient glitch.
- If the NTC warning returns, the sensor or board likely needs service — contact Dometic.
When to call a technician
The NTC open/short warning persists after a power-cycle — the thermistor or control board needs professional replacement; these are not user-serviceable on most CFX3 units.
Applies to
CFX3 35 · CFX3 45 · CFX3 55 · CFX3 55IM · CFX3 75DZ · CFX3 95DZ · CFX3 100
FAQ
What does Dometic Portable Cooler code "Warning 01 / 02 (NTC sensor)" mean?
The cooler's temperature sensor (an NTC thermistor) reads as an open circuit (01) or a short circuit (02). The controller can no longer trust the temperature reading and flags a sensor fault. On dual-zone models this refers to the single-zone / large-compartment sensor.
How do I reset Dometic Portable Cooler Warning 01 / 02 (NTC sensor)?
Switch off and disconnect power for at least 5 minutes, then power back on to see if it was a transient glitch. If the NTC warning returns, the sensor or board likely needs service — contact Dometic.
What is the most common cause of Warning 01 / 02 (NTC sensor) on a Dometic Portable Cooler?
The most likely cause is disconnected, broken, or pinched ntc sensor wire (open circuit, code 01).
Related · Dometic portable cooler
The cooler stopped running on 12/24V DC because the incoming… Warning 03 / 43 (communication)
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Same kind of temperature-sensor fault as Warning 01/02, but … Warning 32 (fan overcurrent)
The cooling fan is drawing more current than allowed, which … Warning 33 (compressor start)
The cooler's controller tried to start the compressor but it… Warning 34 (compressor speed)
The compressor is running but cannot reach or hold its targe…
Sources
- !WARNING 02 NTC short circuit SZ & DZ LARGE | CFX3 Coolers | Support — CFX3 alert & warning codes — Warning 02 (Dometic)
- I see an alert message or warning code | CFX3 Coolers | Support — CFX3 warning code index — Warning 01/02 NTC open/short circuit (Dometic)
Note: Dometic confirms Warning 01 = NTC open circuit and Warning 02 = NTC short circuit (SZ & DZ large compartment) and describes it as an internal sensor fault. Dual-zone models also have Warning 11/12 for the small-zone sensor. Repair generally requires service rather than a DIY fix.
● Last verified 2026-06-29 · compiled from manufacturer documentation. Codes can vary by model year — always cross-check your unit’s manual.