NTC thermistor, a temperature sensor whose resistance drops as it warms
Generic photo: Soumyapatra13 · CC BY-SA 4.0

How to test an NTC thermistor (temperature sensor) and read a resistance chart

NTC thermistors are used in refrigerators, dryers, washers, dishwashers, AC units and water heaters. Resistance falls as temperature rises. You test them by measuring resistance at a known temperature and comparing it with the chart for that exact sensor family.

Cross-checked ~20 min easyBrands: All

Before you start

  • Unplug the appliance or turn off the breaker before opening panels or disconnecting parts
  • Take a photo of the wiring before removing any wire
  • Resistance and continuity tests are done with power OFF and the part isolated

Diagnostic steps

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OnCall Tech is a reference tool for trained technicians and can make mistakes. Always disconnect power and confirm with the manufacturer's documentation before you work.

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How to test an NTC thermistor (temperature sensor) and read a resistance chart · OnCall Tech