E1
Bosch Oven
Severity: CriticalWhat Does This Error Mean?
E1 means the oven has detected a temperature above the safe maximum — either actual overheating or a shorted sensor reading falsely high. Disconnect power and test the temperature sensor before using the oven again.
Affected Models
- Bosch Electric Oven
- Bosch Serie 2 Oven
- Bosch Serie 4 Oven
- Bosch Serie 6 Oven
- Bosch Serie 8 Oven
Common Causes
- Shorted oven temperature sensor reading falsely high
- Actual overheating caused by a stuck heating relay on the control board
- Damaged sensor wire causing a short to ground
- Cooling fan failure allowing cabinet temperatures to spike
How to Fix It
-
Disconnect power immediately.
Turn off the oven at the circuit breaker. E1 can indicate the oven is actively overheating. Do not use the oven again until the fault is identified.
-
Test the temperature sensor.
Once the oven has cooled completely, disconnect the sensor and test resistance. A near-zero reading confirms a short — replace the sensor. A normal resistance reading suggests the control board relay is the fault.
-
Check the cooling fan.
Bosch ovens have a cooling fan that protects the electronics. If the fan has failed, the cabinet can overheat and trigger E1. Listen for the fan running during and after a cycle.
-
Replace the control board if the sensor is fine.
If the sensor tests within spec and E1 still occurs, a relay on the control board is stuck in the ON position. This requires board replacement — contact Bosch service.
When to Call a Professional
If the temperature sensor tests fine but E1 persists, the control board has a relay stuck in the ON position — causing the oven to heat continuously. A Bosch technician must replace the board.