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Error code reference

Whirlpool Microwave Error Code F4E3

Hood NTC failure

Whirlpool codesWhirlpool microwave codes

Hood NTC failure - The hood NTC temperature sensor has failed.

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What F4E3 means on a Whirlpool microwave

The F4E3 error code on a Whirlpool microwave indicates a failure in the hood NTC (Negative Temperature Coefficient) temperature sensor. This sensor is located in the hood section of over-the-range microwave models and is responsible for monitoring the temperature of the ventilation area, typically to detect heat rising from the cooktop below. NTC sensors work by decreasing their electrical resistance as temperature increases, and the control board reads this resistance to determine the actual temperature. When the board receives a signal outside the expected resistance range, whether open circuit, short circuit, or an out-of-range reading, it triggers the F4E3 fault.

The hood NTC sensor is a separate component from the cavity or magnetron temperature sensors. Its primary job is to protect the appliance from overheating due to stovetop cooking activity beneath the unit. A failure in this sensor can prevent the microwave from operating normally, as the control board loses confidence in the thermal data it needs to manage ventilation fan speed and overheat protection. This is a safety-oriented sensor, so the control board treats its failure as a serious fault.

Common causes include a physically damaged or disconnected sensor, wiring harness issues between the sensor and the control board, or an NTC thermistor that has drifted out of specification due to age or heat exposure. In some cases, moisture or grease buildup in the hood area can degrade the sensor or its wiring connections. A full diagnosis requires inspecting the sensor, checking its resistance with a multimeter, and verifying continuity through the associated wiring harness.

Source: manufacturer service documentation.

Common causes of F4E3

  1. 01

    Faulty hood NTC thermistor

    Part replacement

    The NTC thermistor itself may have failed, producing a resistance value outside the range the control board expects. Testing the sensor with a multimeter and comparing the reading against the expected resistance curve will confirm this.

  2. 02

    Disconnected or damaged wiring harness

    Wiring / connection

    The wiring connecting the hood NTC sensor to the control board may have come loose, corroded, or been damaged by heat or grease. Inspect the connector at both the sensor end and the board end for signs of burning, corrosion, or loose pins.

  3. 03

    Open circuit in sensor circuit

    Part replacement

    A break in the sensor wire creates an open circuit, causing the control board to read no signal at all. This is often the result of a wire that has been pinched or worn through over time.

  4. 04

    Grease or moisture contamination

    Wiring / connection

    Heavy grease or moisture buildup in the hood area can degrade the sensor body or its electrical connections, causing erratic or out-of-range resistance readings. Cleaning the area and inspecting for contamination is a useful early diagnostic step.

  5. 05

    Failed control board

    Part replacement

    If the sensor and wiring test within normal parameters, the control board itself may be misreading the sensor signal. This is a less common cause but should be considered after all other components have been ruled out.

See the test procedure for each cause

Frequently asked questions about F4E3

What does F4E3 mean on a Whirlpool microwave?
F4E3 indicates a failure in the hood NTC temperature sensor, which is the thermistor that monitors heat levels in the ventilation hood area of your over-the-range microwave. The control board has detected that the sensor is producing a reading outside its acceptable range, which could indicate an open circuit, short, or a sensor that has drifted out of specification. The microwave will typically stop normal operation until the fault is resolved.
Can I fix the F4E3 error myself?
A knowledgeable DIYer can diagnose this error by inspecting the hood NTC sensor and its wiring harness for visible damage, loose connectors, or corrosion. Using a multimeter to test the resistance of the NTC thermistor can confirm whether the sensor has failed. Replacing the sensor is a manageable repair if you are comfortable working with appliance wiring, but always unplug the microwave before beginning any inspection or repair.
Is it safe to use my microwave while it shows the F4E3 code?
It is not recommended to continue using the microwave while F4E3 is active. The hood NTC sensor is part of the appliance's overheat protection system, and operating without a functioning sensor means the control board cannot properly monitor heat levels in the hood area. This could allow the unit to overheat without triggering a protective response.
Will resetting the microwave clear the F4E3 error?
Unplugging the microwave for a minute and restoring power may temporarily clear the error display, but if the underlying sensor or wiring fault still exists, the code will return. A reset is useful for confirming whether the fault is intermittent, but it does not fix the root cause. A proper repair requires diagnosing and addressing the sensor or wiring issue.
How much does it cost to repair an F4E3 error on a Whirlpool microwave?
If only the hood NTC sensor needs to be replaced, parts costs are typically in the range of $15 to $50, and the repair is relatively straightforward. If the wiring harness requires repair or replacement, costs may be slightly higher. A professional appliance technician repair, including labor, generally runs in the range of $100 to $250 depending on your location and the extent of the damage.

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