Bosch Oven Error Code Er3 — Oven Overheating
What this means
Error Er3 indicates the oven's internal temperature has risen dangerously above the set temperature. This is a critical safety shutdown. Common causes include a faulty temperature sensor giving incorrect readings, a stuck relay on the control board keeping the heating element on, or a blocked cooling vent.
Alternate codes: E115
Step-by-step fix
4 stepsTurn off and let cool
Turn off the oven immediately and open the door to allow it to cool. Do not use the oven until the issue is resolved.
Wait at least 30 minutes before beginning any troubleshooting.
Check the door seal
Inspect the oven door gasket for damage or gaps that could affect temperature regulation.
Test the temperature sensor
A faulty sensor could be telling the board the oven is cooler than it is, causing it to overheat. Test for ~1,080 ohms at room temperature.
Check the cooling fan
Bosch ovens have a cooling fan that prevents overheating. Verify it runs when the oven is on.
When to call a professional
Overheating is a safety hazard. If the sensor tests normal, the control board relay may be stuck and needs professional diagnosis.
Information compiled from manufacturer service manuals, official troubleshooting documentation, and appliance repair industry resources. This guide is for informational purposes only — always consult a qualified technician for complex repairs.
Learn more about our sourcesParts you may need
Links may earn us a commission at no extra cost to you. We only recommend parts relevant to this repair.