JennAir Combination Wall Oven Code F4 E0: microwave inverter

What F4 E0 means

On JennAir combination wall ovens with a built-in microwave, F4 E0 means there may be a problem with the microwave inverter or the associated wiring. The inverter feeds power to the magnetron, so when it misbehaves the microwave cannot heat. The display shows F4 E0 and the microwave side stops. Cold leftovers after a full cycle are the sign most owners notice. The light and keypad may still work.

Common causes of F4 E0

Microwave inverter that has failed
Wiring between the inverter and the microwave control
Inverter not receiving or sending the signal it needs

✓ One safe check you can try

1. Press Cancel and try opening and closing the microwave door. 2. Reset power by turning the breaker off and on after a one-minute wait, giving the inverter a second try. 3. Put a cup of water in the microwave for a twenty-second test. 4. Never run the microwave empty. 5. Should F4 E0 return, leave the oven off and tell us it is the inverter.

! Why to stop there

The inverter works at high voltage and holds a charge after power is cut.
Testing it takes proper tools and training.
Replacing the magnetron without checking the inverter would waste money.

Opening a panel yourself does not automatically cancel a manufacturer warranty, but it can cause accidental damage, and some manufacturers set their own service conditions. Check your warranty terms, or ask us, before deciding.

→Same appliance

Other Wall Oven codes

FC E6JennAir Wall Oven Code FC E6: Wi-Fi power module FC E7JennAir Wall Oven Code FC E7: Oven did not connect to router FC E8JennAir Wall Oven Code FC E8: Registration error FC E9JennAir Wall Oven Code FC E9: Wi-Fi power module wiring Feature Not AvailableJennAir Wall Oven Message "Feature Not Available": Follow the Prompt on the Display Flashing Time, Clock, 12:00, Power Loss or Enter TimeJennAir Wall Oven Display Flashing Time or 12:00: Set the clock after power loss Locked, Lock or LocJennAir Wall Oven Display Locked, Lock or Loc: Controls and door are locked Press Cancel to ResetJennAir Wall Oven Message "Press Cancel to Reset": Clear and power cycle

F4 E0F4 E0 questions

What does a microwave inverter do?

It supplies the controlled high-voltage power the microwave needs to heat food. When it fails, you get F4 E0 and no microwave heat. The inverter is the unit that supplies power to the magnetron, so a failure there stops heating.

Will the regular oven still work?

In many cases yes, because the code concerns the microwave side. We still suggest a check to be sure the problem has not spread. Cooking in the main oven is usually possible while the microwave side waits.

Is the repair done in your shop or at home?

We do it at your home in Houston. You get a written price first, and our work carries a 30-day workmanship warranty. Ask about the written price, which includes the inverter and the labor.