Samsung Dishwasher Thermistor Replacement — What This Part Does
The thermistor is the temperature sensor that tells the control board how hot the water is during the wash cycle. The dishwasher uses this reading to decide when to stop heating and when to advance to the next phase. When the thermistor drifts out of range, opens internally, or sends a signal the control can’t read, the dishwasher either stops heating or aborts the cycle completely because it thinks the water temperature is wrong.
Most thermistor failures happen because the sensor element itself goes bad over time, but loose or corroded wiring at the connector and improper seating at the pump housing gasket (especially after earlier service) also cause false readings. If the sensor tests out of range with a multimeter on the ohm setting, replacement is the fix.
Signs It Needs Replacing
- Dishwasher won’t heat water The wash cycle runs but dishes come out cold and dirty because the control isn’t getting a valid temperature signal.
- Cycle stops partway through The dishwasher aborts mid-cycle and may display a fault code related to temperature or the thermistor circuit.
- Unusually long or short wash times The control misreads water temperature and either overheats or ends heating too soon, throwing off the cycle timing.
- Temperature fault code on display The control flags a thermistor or temperature sensor problem because the sensor reading is out of the expected range.
- Sensor reads open or out of range on a multimeter Testing the thermistor on the ohm setting (not continuity) shows a resistance value that doesn’t match the temperature chart for your model.
- Corroded or damaged connector at the sensor Visual inspection shows burned terminals, water intrusion, or broken wires at the thermistor harness plug.
How to Replace It
- Unplug the dishwasher and shut off the water supply at the valve under the sink.
- Remove the lower front panel or kickplate by pulling out or unscrewing the fasteners, then tilt the dishwasher back or pull it out from the cabinet far enough to access the base.
- Locate the thermistor on the pump housing or sump area (consult your model’s service diagram if needed).
- Disconnect the wire harness connector from the thermistor, then use a multimeter on the ohm setting to test the old sensor against the temperature resistance chart for your model (continuity-only testing is not correct for this sensor).
- If the reading is out of range, remove the mounting screws or clips securing the thermistor to the pump housing or bracket.
- Pull out the old thermistor and gasket (if present), then install the new thermistor with a fresh gasket and seat it firmly into the housing to prevent leaks.
- Reconnect the wire harness, reinstall any covers or lower panels, and slide the dishwasher back into place.
- Restore water and power, then run a test cycle or enter service mode to confirm the control reads temperature correctly and there are no leaks at the sensor mount.
- Monitor the first full cycle to verify normal heating and cycle completion without fault codes.
The Part You Need
| Part | Notes |
|---|---|
| Samsung dishwasher thermistor (temperature sensor) | Amazon | Common part numbers include DD32-00005A (also listed as AP4579881, PS4222316) and DD32-00009A. Check the model and serial plate inside the dishwasher door or on the side of the tub to find your exact replacement part number, or search by your full model number on a Samsung parts site. |
| Thermistor gasket or seal (if sold separately) | Amazon | Some thermistor assemblies include a gasket, others require ordering it separately. Inspect the pump housing mounting point during disassembly to confirm fitment. |
Related Error Codes
If this part is failing you may also see one of these codes:
- Samsung Dishwasher 3C error code
- Samsung Dishwasher 3E error code
- Samsung Dishwasher 4C error code
- Samsung Dishwasher 5C error code
- Samsung Dishwasher 9E error code
- Samsung Dishwasher Ap error code
- Samsung Dishwasher Be error code
- Samsung Dishwasher Ce error code
- Samsung Dishwasher Hc error code
- Samsung Dishwasher He error code
When to Call a Pro
If you’ve replaced the thermistor and tested it with a multimeter but the dishwasher still flags a temperature fault or won’t heat, the problem is likely in the wiring harness or the control board itself. Diagnosing a harness short or a failed board input requires a service manual, wiring diagram, and experience tracing sensor circuits. A qualified appliance tech can pinpoint the fault without swapping more parts and can also handle any leak-testing or pump-housing work if the sensor mount area shows signs of water damage or corrosion.