mypros+
Error code reference

Maytag Microwave Error Code E03

Convection motor or convection heater circuit is open.

Maytag codesMaytag microwave codes

Convection motor or convection heater circuit is open.

First step from the service manual

Check if motor and/or heater are unplugged; inspect wiring and PCB assembly.

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 E03.

  • 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 E03 means on a Maytag microwave

E03 on a Maytag microwave indicates the control board has detected an open circuit in the convection motor, the convection heater, or both. An open circuit means the board is sending power to the component but receiving no confirmation of continuity or operation. This can result from a failed motor winding, a burned-out heater element, a disconnected wiring harness, or a fault on the PCB assembly itself. The board flags E03 when it cannot verify that either the convection motor is spinning or the convection heater is energized during a convection cooking cycle.

For homeowners, this error means your microwave's convection cooking function has stopped working. Convection mode uses a fan motor to circulate hot air and a heater element to generate heat, similar to a standard oven. When E03 appears, one or both of these components is not operating. Standard microwave functions may still work depending on your model, but convection baking and roasting will not.

The first step in diagnosing E03 is checking whether the convection motor or heater wiring has come loose. Connectors can vibrate free over time. If all connections are secure, the next step is testing the motor and heater element for continuity with a multimeter, then inspecting the PCB assembly for visible damage.

Source: manufacturer service documentation.

Common causes of E03

  1. 01

    Disconnected or loose wiring harness to convection motor or heater

    Wiring / connection

    Vibration during normal use can cause wiring connectors to work loose from the convection motor or convection heater terminals. This creates an open circuit that triggers E03 without any component being actually defective.

  2. 02

    Burned-out convection heater element

    Part replacement

    The convection heater element can fail internally, breaking the circuit and registering as open on the control board. A multimeter test across the heater terminals will show no continuity when this has occurred.

  3. 03

    Failed convection motor

    Part replacement

    The convection fan motor can develop an open winding due to overheating or age, causing it to draw no current. The control board interprets this as an open circuit and displays E03.

  4. 04

    Faulty PCB assembly

    Part replacement

    If the wiring, motor, and heater all test good, the PCB assembly may have a damaged relay or trace that prevents it from properly powering or sensing the convection components. This is the least common cause but requires board replacement to resolve.

See the test procedure for each cause

Frequently asked questions about E03

What does E03 mean on a Maytag microwave?
E03 means the control board has detected an open circuit in the convection motor, the convection heater, or both. The board cannot confirm these components are receiving or using power during a convection cycle. The cause can range from a loose wiring connector to a failed heater element, a failed motor, or a fault in the PCB assembly.
How do I fix E03 on a Maytag microwave?
Start by unplugging the microwave and checking whether any wiring connectors to the convection motor or convection heater have come loose. Reconnect any loose connectors and test the unit. If connections are secure, use a multimeter to test the heater element and motor for continuity. A reading of infinite resistance on either component confirms it has failed and needs replacement. If both test good, the PCB assembly should be inspected next.
Can I still use my Maytag microwave with E03 showing?
Standard microwave functions may still operate on some Maytag models when E03 is active, since the error is specific to the convection system. However, convection cooking modes will not work and should not be attempted while the fault is present. Using the convection function with a known open circuit in the heater or motor can cause further damage to the control board or wiring.
How much does it cost to fix E03 on a Maytag microwave?
If the fix is just reseating a loose wiring connector, there is no parts cost and only your time. A replacement convection heater element typically costs between $20 and $60 in parts, and a convection motor is usually in the $30 to $80 range. A PCB assembly is the most expensive repair, often $80 to $200 or more in parts alone. Adding professional labor generally runs $75 to $150 per hour, so if the unit is older, comparing repair cost to replacement cost is worth doing before ordering parts.
Is E03 on a Maytag microwave a hard repair to do yourself?
Checking and reseating wiring connectors is a low-difficulty repair that most homeowners can handle after unplugging the unit and removing the outer cabinet. Testing the heater element and motor with a multimeter requires basic familiarity with continuity testing but is manageable for a careful DIYer. Replacing the PCB assembly involves more disassembly and working near high-voltage capacitors that can retain a dangerous charge even after unplugging; discharge the capacitor before working near it, or have a technician handle a board-level repair.

Related Maytag microwave codes

All Maytag microwave codes
View all 62 Maytag microwave codes

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

Get Started

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