mypros+
Error code reference

Whirlpool Microwave Error Code FDE3

Hood fan relay failure

Whirlpool codesWhirlpool microwave codes

Hood fan relay failure - The relay controlling the hood fan has failed.

MyPros+ Max

Get the full diagnostic procedure for FDE3.

  • 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 FDE3 means on a Whirlpool microwave

The FDE3 error code on a Whirlpool microwave indicates a hood fan relay failure. The relay responsible for controlling the exhaust or ventilation fan in the hood assembly has malfunctioned. This relay acts as an electrically controlled switch, receiving a low-voltage signal from the control board and using it to switch the higher-voltage circuit that powers the fan motor. When the control board detects that this relay is not responding correctly or has failed in an open or shorted state, it triggers the FDE3 fault code and typically disables operation to prevent further damage.

The hood fan relay can be located on the main control board itself or on a dedicated relay board, depending on the specific Whirlpool model. A failed relay may present in several ways: the fan may run continuously without a command, fail to start at all, or cause erratic fan behavior. Over time, the relay contacts can burn, weld together, or corrode, all of which compromise the relay's ability to switch the fan circuit properly.

Diagnosing FDE3 generally involves inspecting the control board for visible signs of heat damage or burnt relay contacts, testing relay coil resistance, and verifying that the fan motor itself is not drawing excess current that may have caused the relay to fail prematurely. If the fan motor is shorted or seized, it may have damaged the relay, so both components should be evaluated before replacing only the relay or control board.

Source: manufacturer service documentation.

Common causes of FDE3

  1. 01

    Failed relay on control board

    Part replacement

    The relay component on the main control board can burn out or have its contacts weld together over time. Visible scorch marks or a burnt smell near the board are common indicators.

  2. 02

    Shorted or seized fan motor

    Part replacement

    A fan motor drawing excessive current due to a short or mechanical seizure can cause the relay to fail prematurely. Check that the fan blade spins freely and that the motor windings are not shorted.

  3. 03

    Failed main control board

    Part replacement

    If the relay is integrated into the control board circuitry, broader board failure can trigger FDE3. Inspection for damaged traces, burnt components, or swollen capacitors near the relay circuit can help confirm this.

  4. 04

    Loose or corroded wiring connections

    Wiring / connection

    Poor connections between the control board relay output and the fan motor can mimic relay failure. Inspect the wiring harness connectors at both the board and motor for corrosion, looseness, or heat damage.

See the test procedure for each cause

Frequently asked questions about FDE3

What does FDE3 mean on a Whirlpool microwave?
FDE3 indicates a hood fan relay failure on your Whirlpool microwave. The relay that controls the exhaust or ventilation fan has been detected as non-functional by the control board. This can mean the relay contacts have failed open or shorted, or that the control board can no longer properly operate the relay circuit.
Can I fix the FDE3 error myself?
Some experienced DIYers may be able to address FDE3 by inspecting wiring connections for looseness or corrosion, which requires no parts replacement. However, if the relay or control board itself has failed, repair involves working with high-voltage appliance components and soldering or board replacement, which is best handled by a qualified technician. Attempting board-level repairs without proper training carries risk of injury and further damage.
Is it safe to use my Whirlpool microwave while the FDE3 code is active?
It is not recommended to continue using the microwave while FDE3 is active. A failed hood fan relay means the exhaust fan may not operate correctly, which can allow heat and steam to build up and potentially cause further damage to internal components. Discontinue use until the fault is diagnosed and repaired.
How much does it cost to repair the FDE3 error on a Whirlpool microwave?
Repair costs depend on which component has failed. Wiring inspection and connection cleaning may cost only a service call fee, typically in the range of $75 to $150. Relay or control board replacement, including parts and labor, generally ranges from $150 to $350 or more depending on the specific model and local labor rates.
Will resetting my Whirlpool microwave clear the FDE3 error code?
Resetting the microwave by unplugging it or cutting power at the breaker for a few minutes may temporarily clear the FDE3 code, but if the underlying relay or board fault remains, the code will return. A reset does not repair the failed component, so a proper diagnosis is still necessary to resolve the fault permanently.

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