How to Replace a Maytag Dishwasher Temperature Sensor (Thermistor)

The temperature sensor (thermistor) in a Maytag dishwasher monitors water temperature throughout the cycle, telling the control board when water is hot enough for detergent activation and when to engage or disengage the heating element. A failed sensor causes the control board to either run the heater continuously (overheating water and potentially damaging plastic components) or never heat (cold washes with poor cleaning). Maytag dishwashers may display F3E1 or F3E2 error codes when the temperature sensor circuit is open or shorted.

The thermistor is a small probe mounted in the sump area at the bottom of the tub, directly in the water stream. It is one of the simplest components to replace on a Maytag dishwasher because it is accessible from inside the tub without removing any panels on most models.

Before You Start

• Tools needed: Phillips #2 screwdriver or Torx T20 (model-dependent), multimeter, towels
• Parts needed: Temperature sensor/thermistor ($15-$40)
• Time required: 15-25 minutes
• Difficulty: Beginner
• Safety warning: Disconnect power at the circuit breaker before testing or replacing the sensor. The sensor itself carries low voltage, but the wiring passes near high-voltage components.

Step-by-Step Instructions

Step 1: Verify the temperature sensor has failed

Disconnect power at the breaker. Remove the lower dish rack and the filter assembly (quarter-turn counter-clockwise on the cylindrical filter, lift the flat mesh). The temperature sensor is a small cylindrical or oval-shaped probe mounted in the sump area or on the sump housing wall, partially submerged in the standing water. It has a two-wire connector. Disconnect the wire connector from the sensor. Set your multimeter to resistance (ohms) and measure across the sensor terminals. At room temperature (approximately 70F/21C), a healthy thermistor reads approximately 50,000-55,000 ohms (50K NTC type, which is standard on Whirlpool Corporation dishwashers). If the reading is open circuit (OL) or near zero ohms, the sensor is failed.

Step 2: Locate the sensor in the tub

With the lower rack and filters removed, look at the sump area at the center bottom of the tub. The temperature sensor is usually mounted to one side of the sump near the heating element area, or integrated into a plastic housing on the sump wall. On some Maytag models, it is clipped to the underside of the lower spray arm support near the filter housing. It is a small component (about the size of a thumb) with a wire lead running along the tub floor to a connector. Follow the wire to find the connector point.

Step 3: Remove the old sensor

The sensor is held in place by a single mounting screw, a twist-lock clip, or a push-in grommet depending on the model. Remove the mounting fastener. Gently pull the sensor straight out of its housing. If it is sealed with a grommet into the sump wall, note how the grommet seats for reinstallation. On models where the sensor clips into the sump from above, it simply unclips and lifts out. Do not force the sensor as excessive force can crack the sump housing (which is a much more expensive repair).

Step 4: Disconnect the wire connector

Follow the sensor wire to its connector. On some models, the connector is accessible from inside the tub. On others, you need to reach under the tub or remove the lower access panel (two 1/4-inch hex screws) to access the connector on the underside of the sump. Press the locking tab and disconnect. If the connector is under the tub, you will need to feed the new sensor wire through the same routing path.

Step 5: Install the new temperature sensor

Route the new sensor wire along the same path as the old one. Insert the sensor probe into its mounting location in the sump. Secure with the mounting screw, twist-lock clip, or grommet. Ensure the seal is watertight if the sensor penetrates the sump wall. Connect the wire harness to the control board connector until it clicks. Verify the sensor probe is positioned in the water flow path (it must be submerged during operation to accurately read water temperature).

Step 6: Verify with a resistance test

Before reassembling, verify the new sensor reads correctly with your multimeter. At room temperature, confirm approximately 50K ohms across the terminals. This confirms the new part is functional and the connector is making good contact.

Step 7: Reassemble and clear error codes

Reinstall the filter assembly and lower rack. Reinstall the access panel if removed. Restore power at the breaker. If F3E1 or F3E2 was displayed, the code should clear after the sensor circuit reads normally. If the code persists, power-cycle at the breaker for 60 seconds. Run a Normal cycle and monitor: the heating element should engage during the wash phase (you can feel increasing warmth through the tub wall) and disengage when water reaches approximately 140F.

Step 8: Monitor the first few cycles

The control board uses temperature data to determine cycle duration and heater activation. With a new sensor providing accurate readings, cycle times may change slightly compared to when the old sensor was failing. If cycles seem much longer than before (more than 30 minutes longer), the new sensor may be reading low, causing the board to run the heater longer. This is rare with a correct replacement part but possible with aftermarket sensors that have different resistance curves.

How the Temperature Sensor Affects Maytag Cycle Performance

The thermistor directly controls two critical functions: heater engagement (turns on when water is below target temperature) and cycle phase advancement (the control board moves from wash to rinse when water reaches the programmed temperature threshold). On Maytag's PowerBlast cycle, the target temperature is higher than Normal, so the sensor must be accurate to prevent either undershoot (poor cleaning) or overshoot (potential damage, excess energy use). A sensor reading 10% low causes the heater to run longer and hotter than necessary. A sensor reading 10% high causes the board to skip heating prematurely, resulting in cold washes.

The same F#E# diagnostic system used across all Whirlpool Corporation brands applies to Maytag: F3E1 typically indicates an open sensor circuit (broken wire or failed sensor), while F3E2 indicates a shorted sensor (sensor resistance near zero).

Troubleshooting After Replacement

If issues persist with the new sensor:

• Verify you installed the correct resistance type. Maytag dishwashers use 50K NTC thermistors. Using a 10K or 100K thermistor (from a different appliance) will cause incorrect temperature readings
• Check the wiring between the sensor and the control board for damage, pinched insulation, or corroded connectors
• If F3E1 persists with a good sensor installed, the control board input circuit may have failed (requires board replacement)
• Verify the sensor is actually submerged in water during operation. A sensor mounted above the water line reads ambient air temperature rather than water temperature

When to Call a Professional

Contact a professional if:

• The error code persists after sensor replacement with confirmed correct resistance, suggesting a board-level fault
• You cannot locate the sensor in your specific model (some models have it in an unusual location)
• The heating element ran continuously before you noticed the issue, potentially damaging other components

Cost Comparison: DIY vs Professional

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FAQ

Q: Can a bad temperature sensor damage my Maytag dishwasher? A: Yes. A sensor that reads low (tells the board water is colder than actual) causes the heating element to run excessively, potentially overheating the tub, warping plastic components, or degrading the door gasket prematurely. If your dishwasher seems to be running very hot or cycles are unusually long, the temperature sensor should be tested promptly.

Q: Is the temperature sensor the same part as the turbidity sensor? A: No. These are different sensors. The temperature sensor (thermistor) measures water temperature. The turbidity sensor measures water clarity (how dirty the water is) and is used by some models to automatically adjust cycle duration. They are mounted in different locations and have different resistance characteristics. Your Maytag may have both.

Q: Does the 10-year Maytag warranty cover the temperature sensor? A: No. The 10-year limited warranty covers only the stainless steel tub, racks, and chopper blade. The temperature sensor is a $15-$40 part covered under the standard 1-year warranty. It is one of the cheapest and easiest components to replace on a Maytag dishwasher.

Q: How long do temperature sensors typically last on Maytag dishwashers? A: Thermistors are solid-state components with no moving parts. They typically last 8-15 years. Failure is usually due to prolonged exposure to high temperatures degrading the sensor material, or corrosion of the wiring from water exposure. Maytag's heavy-duty cycles (PowerBlast, Heavy Duty) expose the sensor to higher temperatures more frequently, which can shorten lifespan slightly compared to standard-use dishwashers.

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