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.
Accuracy notes
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.
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 supply… Warning 03 / 43 (communication)
An internal communication fault between the cooler's electronic… Warning 11 / 12 (NTC sensor)
Same kind of temperature-sensor fault as Warning 01/02, but for the… Warning 32 (fan overcurrent)
The cooling fan is drawing more current than allowed, which the… Warning 33 (compressor start)
The cooler's controller tried to start the compressor but it did not… Warning 34 (compressor speed)
The compressor is running but cannot reach or hold its target speed, so…
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)
● Checked against 2 manufacturer documents · Last verified 2026-06-29 · compiled from manufacturer documentation. Codes can vary by model year — always cross-check your unit’s manual. How we verify