mypros+
Error code reference

Whirlpool Microwave Error Code F8E5

Exhaust air template detector (exhaust air temperature sensor) failure.

Whirlpool codesWhirlpool microwave codes

Exhaust air template detector (exhaust air temperature sensor) failure.

First step from the service manual

Press CANCEL - CANCEL - START, verify failure code, then press CLOCK/OPTIONS to display exhaust air temperature sensor reading. Verify reading is at room temperature (50°F to 90°F).

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

MyPros+ Max

Get the full diagnostic procedure for F8E5.

  • Step-by-step tests with expected resistance, voltage, and continuity values
  • Wiring diagram references and connector pinouts from the OEM service manual
  • Verified part numbers when replacement is required
Get the full procedure

$29/month · Cancel anytime · Or $9.95 3-day pass

What F8E5 means on a Whirlpool microwave

The F8E5 error code indicates the control board has detected a failure in the exhaust air temperature sensing circuit, specifically involving the HF NTC thermistor. This thermistor monitors the temperature of air being exhausted from the microwave cavity. The code triggers when the control board reads a value from this sensor that falls outside the expected resistance range, which can indicate an open circuit, a short, or a thermistor that has drifted out of calibration. The first diagnostic step is to pull a live reading from the sensor through the built-in diagnostics mode to determine whether the thermistor is reading within the normal room-temperature window of 50°F to 90°F.

For homeowners, this error means your microwave's built-in temperature sensor for the exhaust air has stopped communicating correctly with the main control board. Think of it as a safety thermometer that watches the air leaving the microwave. When it stops sending a reliable signal, the microwave flags F8E5 and may limit or stop operation to prevent overheating. The problem could be a failed sensor, a broken wire connection between the sensor and the board, or in some cases a faulty control board that is misreading a good sensor. Running the diagnostics check described below is the essential first step before replacing any parts.

Source: manufacturer service documentation.

Common causes of F8E5

  1. 01

    Failed HF NTC thermistor

    Part replacement

    The thermistor itself has failed, producing a resistance value that is either open (infinite resistance) or shorted (near-zero resistance), both of which the control board reads as out-of-range. This is the most common hardware cause of F8E5 and requires replacing the thermistor.

  2. 02

    Loose or damaged wiring harness to HF NTC thermistor

    Wiring / connection

    The connector or wiring between the HF NTC thermistor and the control board has become loose, corroded, or broken, interrupting the signal. This can mimic a failed thermistor and should be inspected before ordering a replacement sensor.

  3. 03

    Thermistor reading outside room-temperature range due to actual overheating

    Wiring / connection

    If the microwave has been running under heavy use or with blocked ventilation, the exhaust air temperature may genuinely be elevated, causing the sensor to read outside its expected window. Allowing the unit to cool and checking airflow clearance may resolve the error without part replacement.

  4. 04

    Faulty main control board

    Part replacement

    If the thermistor and wiring both test good but F8E5 persists, the control board may be misinterpreting the thermistor signal due to a failed input circuit. This is the least likely cause and should only be considered after the sensor and wiring are confirmed good.

See the test procedure for each cause

Frequently asked questions about F8E5

What does the F8E5 error code mean on a Whirlpool microwave?
F8E5 means the control board has detected a failure in the exhaust air temperature sensor circuit, specifically the HF NTC thermistor. This thermistor monitors the temperature of air exiting the microwave cavity. The board flags F8E5 when the sensor's signal falls outside the acceptable resistance range, which usually points to a failed thermistor, a wiring issue, or a genuine overheating condition.
How do I fix the F8E5 error on my Whirlpool microwave?
Start by entering Diagnostics mode using the sequence CANCEL-CANCEL-START, then press WARM HOLD to read the live HF NTC thermistor value. If the reading is outside 50°F to 90°F and the microwave is at room temperature, the thermistor is likely failed and needs replacement. Before ordering parts, inspect the wiring harness connector at the thermistor for looseness or corrosion, since a bad connection produces the same error and costs nothing to fix.
Is it safe to use my Whirlpool microwave when F8E5 is displayed?
Operating the microwave with an active F8E5 error is not recommended. The HF NTC thermistor is part of the thermal protection system that monitors exhaust air temperature. With this sensor failed, the microwave cannot accurately detect an overheating condition, which removes a key safeguard. Stop using the unit until the thermistor is tested and replaced if necessary.
How much does it cost to repair a Whirlpool microwave F8E5 error?
If the fix is a loose wiring connector, the repair costs nothing beyond your time. An HF NTC thermistor replacement part typically runs $15 to $40 depending on the model, and the repair is within reach for a confident DIYer comfortable working inside a microwave after discharging the high-voltage capacitor. If the control board is the cause, board replacement costs $80 to $180 for the part, and professional labor typically adds $75 to $150, at which point evaluating the appliance's age and overall value is worth doing.
Can I check the HF NTC thermistor myself before calling a repair technician for F8E5?
Yes. Use the built-in diagnostics mode (press CANCEL-CANCEL-START, then WARM HOLD) to read the live thermistor value directly from the control panel. A reading between 50°F and 90°F when the microwave is at room temperature means the sensor is functioning correctly and the problem may be intermittent or wiring-related. A reading well outside that range, or a blank reading, points to a failed thermistor or an open circuit in the harness. You can also test the thermistor's resistance directly with a multimeter once the microwave is unplugged and the capacitor is discharged.

Related Whirlpool microwave codes

All Whirlpool microwave codes
View all 141 Whirlpool microwave codes

78,000+ service manuals · 160,000+ error codes · 55+ brands

Get Started

$29/month · Cancel anytime · Or $9.95 3-day pass