How do I fix Bosch microwave error E05?

Step 1: Power cycle the oven. Step 2: Visually inspect the heating element. Step 3: Test the heating element. Step 4: Check the temperature sensor. Step 5: For gas: Check the igniter. Step 6: Replace the faulty component

E05 Magnetron not heating - no microwave output

serious

The Bosch E05 error code on your microwave indicates: Magnetron not heating - no microwave output. This typically requires troubleshooting the heating system.

Bosch Microwave Affects 1 model

What Causes Error E05

high likelihood #1

Heating element burned out

The bake or broil element has broken or developed a visible crack/burn spot.

medium likelihood #2

Temperature sensor out of range

The oven sensor reads incorrectly, causing the control board to think the oven isn't heating.

high likelihood #3

Igniter failure (gas models)

The hot surface igniter is too weak to open the gas valve, preventing the burner from lighting.

low likelihood #4

Control board relay failure

The relay on the board that sends power to the heating element has failed.

How to Fix Error E05

Step 1: Power cycle the oven

Turn off the circuit breaker for 2 minutes, then turn it back on. This resets the control board.
Step 2: Visually inspect the heating element

Look at the bake element (bottom of oven) and broil element (top). Look for visible breaks, blisters, or burn marks. If you see any bright spots when the oven is trying to heat, the element is failing.

⚠️ The oven and element will be extremely hot during this visual check — do not touch.
Step 3: Test the heating element

With the oven unplugged or breaker off, disconnect one wire from the element and test continuity. Bake elements typically read 20-50 ohms. Infinite resistance means it's broken.

⚠️ Always verify power is OFF before touching any wiring.
Step 4: Check the temperature sensor

Test the oven temperature sensor probe (usually at the top rear of the oven cavity). At room temperature it should read approximately 1,100 ohms. Far above or below this means it needs replacement.
Step 5: For gas: Check the igniter

Watch the igniter when the oven tries to heat. It should glow bright orange/white within 90 seconds and the gas should light. If it glows but the gas never lights, the igniter is too weak — replace it.
Step 6: Replace the faulty component

Heating elements are usually held by 2 screws at the back wall of the oven. Igniters are held by 1-2 screws near the burner tube. Both are straightforward replacements.