Bosch Oven E115 Error Code — What It Means
The E115 (or F115) error code on a Bosch oven signals an overtemperature fault. The control board has detected that the oven cavity temperature has exceeded safe limits and has shut down heating to protect the appliance. This is a safety feature, not a simple sensor glitch.
The code typically points to a failure in the temperature sensing or cooling system. The oven either cannot accurately measure heat, cannot cool itself properly, or a control relay is stuck in the ‘on’ position and continuing to supply power to the heating elements even when it should stop.
Common Causes
- Faulty temperature sensor The oven temperature sensor (probe) has drifted out of range, has internal damage, or poor wiring connections, so the control cannot read cavity temperature accurately.
- Cooling fan failure The cooling fan has stopped running or is running too slowly, preventing proper airflow and allowing heat to build up beyond safe levels.
- Blocked ventilation or airflow Dust, debris, or improper installation have obstructed the cooling vents or fan intake, reducing cooling capacity.
- Stuck relay or faulty control board A relay on the control board is stuck closed or the board logic has failed, keeping heating elements powered continuously even after the setpoint is reached.
- Damaged sensor wiring or connector Corroded, loose, or broken wiring between the sensor and the control board causes intermittent or incorrect temperature readings.
Step-by-Step Fix
- Turn off power at the breaker and allow the oven to cool completely for at least one hour before any inspection or testing.
- Restore power and observe whether the E115 code clears after the cool-down period, indicating a transient overheat rather than a failed component.
- Access and inspect the oven temperature sensor, typically mounted on the rear wall of the cavity, and check for physical damage, corrosion, or loose connector pins.
- Test the temperature sensor by disconnecting it and measuring resistance (consult your model’s service manual for the correct room-temperature resistance value), and replace the sensor if readings are out of specification or unstable.
- Verify the cooling fan operation by listening for fan noise during and after a heating cycle, and visually confirm the fan blades turn freely and the motor is not stalled or clogged with debris.
- Inspect the control board and relay connections for signs of burn marks, arcing, or stuck relays, and replace the relay control board if the sensor and fan test good but the fault persists.
- Run a test bake cycle after repairs to confirm the oven heats normally, the fan cools properly, and the E115 code does not return.
Parts Often Needed
| Part | Notes |
|---|---|
| Oven temperature sensor (probe) | Amazon | Verify the part number for your specific Bosch model. Some transcripts mention 00642855 but always cross-check your serial plate. |
| Cooling fan motor and blade assembly | Amazon | Order the fan assembly matched to your model. Check for both tangential and axial fan types depending on your oven series. |
| Relay control board (oven control board) | Amazon | If sensor and fan are good but overheating persists, the relay board is the likely cause. Verify your model number before ordering. |
When to Call a Pro
Call a qualified appliance technician if you are uncomfortable working with live 240 V circuits, if the error returns after sensor and fan replacement, or if you cannot safely access the control board or rear cavity components. Overheating faults can indicate complex relay or board failures that require diagnostic tools and experience to trace. A pro can also verify that your oven’s ventilation and installation meet manufacturer clearances, which is critical for safe long-term operation.