Error code reference

Whirlpool Dishwasher Error Code 3-1

Thermistor/OWI temperature sensing circuit open

Whirlpool codesWhirlpool dishwasher codes

Thermistor/OWI temperature sensing circuit open - open connector or component in temperature sensing circuit, open or faulty temperature sensor, or faulty temperature sensor input on control.

First step from the service manual

1. Check operation of temperature sensor in Service Diagnostic Cycle. 2. Unplug dishwasher or disconnect power. 3. Check all components and connections in the Temperature Sensing Circuit.

The complete diagnostic procedure includes additional test steps, resistance specifications, wiring diagram references, and component test points.

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What 3-1 means on a Whirlpool dishwasher

The 3-1 error code on a Whirlpool dishwasher indicates that the control board has detected a problem in the temperature sensing circuit. Specifically, the control is reading an open circuit or an out-of-range signal from the temperature sensor (also called a thermistor), which monitors water temperature during the wash and dry cycles. This can point to a failed thermistor, a broken or disconnected wire in the temperature sensing circuit, or a faulty temperature sensor input on the control board itself.

For homeowners, the temperature sensor tells your dishwasher how hot the water is so it can heat it to the right level for cleaning and sanitizing. When the dishwasher cannot get a valid reading from this sensor, it stops the cycle and displays the 3-1 code rather than risk running with water that is too cold or overheated. The dishwasher is not ignoring the problem, it is protecting itself and your dishes.

The most common trigger is a failed thermistor or a loose, corroded, or broken wire connection between the sensor and the control board. Before replacing any parts, technicians should run the Service Diagnostic Cycle to confirm the sensor is actually malfunctioning, then check the full temperature sensing circuit with a multimeter to isolate the fault.

Source: manufacturer service documentation.

Common causes of 3-1

  1. 01

    Failed temperature sensor (thermistor)

    Part replacement

    The thermistor itself has failed internally and is producing an open circuit or a signal outside the expected resistance range. This is the most common cause of the 3-1 code and requires replacing the sensor.

  2. 02

    Open or broken wiring connection in the temperature sensing circuit

    Wiring / connection

    A wire in the harness connecting the thermistor to the control board has broken, come loose, or corroded, interrupting the signal. The dishwasher reads this as an open circuit and triggers the 3-1 code.

  3. 03

    Corroded or disconnected wire harness connector

    Wiring / connection

    The connector plug at the thermistor or control board end of the temperature sensing circuit has corroded pins or has partially unseated, causing an intermittent or complete loss of signal.

  4. 04

    Faulty temperature sensor input on the control board

    Part replacement

    If the thermistor and all wiring check out as good with a multimeter, the control board's sensor input circuit may have failed. This is the least likely cause but should be considered after all other components test correctly.

See the test procedure for each cause

Frequently asked questions about 3-1

What does error code 3-1 mean on a Whirlpool dishwasher?
The 3-1 code means the control board detected an open circuit or faulty signal from the temperature sensor (thermistor). The dishwasher cannot get a valid water temperature reading, so it halts the cycle. The problem is in the temperature sensing circuit, which includes the thermistor, the wiring harness, and the sensor input on the control board.
How do I fix error code 3-1 on my Whirlpool dishwasher?
Start by running the Service Diagnostic Cycle to confirm the sensor is actually faulting. Then unplug the dishwasher and use a multimeter to check resistance across the temperature sensor and continuity through the wiring harness. A healthy thermistor will show a measurable resistance that changes with temperature, not an open line. Replace any component that tests faulty. If all components check out, the control board's sensor input may have failed and the board would need replacement.
Can I still use my Whirlpool dishwasher when it shows the 3-1 error code?
Running the dishwasher with an active 3-1 code is not recommended. Without a working temperature sensor, the control board cannot verify that the water is reaching the proper temperature for cleaning and sanitizing. Cycles may run with water that is too cold to effectively clean dishes or dissolve detergent. Address the fault before resuming normal use.
How much does it cost to fix a 3-1 error on a Whirlpool dishwasher?
If the fix is a loose or corroded wire connection, the repair costs nothing beyond your time. A replacement thermistor typically costs $10 to $40 for the part, and most homeowners comfortable with basic appliance repair can replace it without professional help. If the control board is at fault, parts can run $100 to $250 or more, and professional labor will add to that cost. Diagnose the thermistor and wiring first before committing to a board replacement.
How do I test the temperature sensor on a Whirlpool dishwasher showing a 3-1 code?
Unplug the dishwasher, disconnect the thermistor's wire harness connector, and set your multimeter to measure resistance (ohms). Place the probes on the thermistor terminals. At room temperature, a functioning thermistor will show a specific resistance value listed in your service manual, typically in the range of 10,000 to 50,000 ohms depending on temperature. An open line (OL or infinite resistance) confirms the thermistor has failed and needs to be replaced. Also check the wiring harness for continuity between the sensor and the control board.

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