E05 Magnetron not heating - no microwave output
The Bosch E05 error code on your microwave indicates: Magnetron not heating - no microwave output. This typically requires troubleshooting the heating system.
What Causes This Error
Magnetron failure
highThe magnetron tube that generates microwaves has burned out or lost vacuum integrity.
High voltage diode burned out
highThe diode that converts AC to DC for the magnetron has failed, cutting power to the tube.
High voltage capacitor failure
mediumThe capacitor that stores and doubles voltage for the magnetron circuit is defective.
High voltage transformer failure
lowThe transformer that steps up household voltage to power the magnetron has failed.
How to Fix Error E05
- 1
Power cycle the microwave
Unplug the microwave for 5 minutes, then plug it back in. This resets the control board and clears transient errors.
- 2
Test if it heats at all
Place a microwave-safe cup of water inside and run on high for 60 seconds. If the water is not warm at all, the magnetron or its power supply has failed.
- 3
Listen for the magnetron
When running, you should hear a low hum from the magnetron. If you hear nothing (just the turntable and fan), the magnetron or its power supply isn't activating.
- 4
Check the door switches
Microwave door switches must all be engaged for the magnetron to receive power. Open and close the door firmly, listening for the switches to click.
- 5
Do NOT attempt internal repairs yourself
The high voltage capacitor inside a microwave can store a lethal charge (over 2,000 volts) even when unplugged. Internal microwave repairs should only be done by qualified technicians.
DANGER: Microwave capacitors can retain a lethal electrical charge for hours after unplugging. Never remove the cabinet cover.
Replacement Parts
If the steps above don't fix it, you may need one of these parts:
Magnetron
$60-$150High Voltage Diode
$10-$25High Voltage Capacitor
$15-$35When to Call a Professional
Always call a professional for microwave heating component repairs
- Microwave capacitors store lethal voltage even when unplugged
- Magnetron replacement requires specialized knowledge
- Improper reassembly can cause radiation leakage