Bosch Microwave E17: The Fast Preheat Did Not Finish

What E17 means

On a convection or combination model, you start a fast preheat and the oven stops short, showing E17. The quick-heat function is the demanding one, since it pushes the oven to temperature on a tight schedule. When it cannot reach that point in time, it reports the failure and gives up. Regular cooking may still work, which helps narrow down where the problem lies.

Common causes of E17

Preheat sensor or timing reading incorrectly
Convection heating element weaker than it should be
Control board calibration drifting

✓ One safe check you can try

1. Switch the oven off and let it cool. 2. Start a standard preheat instead of the fast one and set the same temperature. 3. Watch whether it reaches temperature in a normal time. 4. If standard works but fast preheat keeps showing E17, tell us. If neither works, stop and call us.

! Why to stop there

Without a meter, you cannot tell a weak element from a sensor reading error, so guessing wastes money.
Repeated fast preheats on a struggling element add stress to it.
Opening a combination oven to look at the heater exposes high-voltage parts.

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 Microwave codes

E1Bosch Microwave E1: Thermistor Circuit Reads Open E4Bosch Microwave E4: The Thermistor Circuit Reads Shorted E-04Bosch Microwave E-04: Over-the-Range Humidity Sensor Not Reporting E-11Bosch Microwave E-11: Over-the-Range Key Read as Held for a Minute E2Bosch Microwave E2: The Safety Shutoff Stopped Your Cycle E3Bosch Microwave E3: Door Will Not Latch or Release Properly E11Bosch Microwave E11: Moisture Detected at the Control Panel ER1Bosch Microwave ER1: Convection Temperature Sensor Failing

E17E17 questions

Can I still bake while E17 shows up?

Often the standard preheat still works, so you can cook while waiting for a visit. If the oven struggles with that too, stop using it so we can check the heating.

Does E17 mean the element is burned out?

Not necessarily. A fast preheat can fail from a sensor or timing problem even when the element is mostly healthy. A test is needed to know which, and we price in writing.

Is it worth repairing for just the fast preheat?

If you rarely use the fast function, you may live with it. If regular heating also suffers, repair is worthwhile. We tell you what we see and the written price first.