Bosch ER2 — Oven overheat — temperature exceeded safe operating limit

What Bosch ER2 error means on your oven

Error code ER2 indicates that the oven has detected a temperature exceeding the safe operating limit. The high-limit thermostat or the temperature sensor has registered temperatures significantly above the set point. This is a safety code — the oven immediately shuts off all heating elements and locks out operation until the issue is resolved. If you encounter the bosch er2 error, professional Bosch oven repair may be needed.

Symptoms

• The oven shuts off abruptly and displays ER2
• The oven door may lock (safety lockout mode, similar to self-clean)
• The oven cavity feels significantly hotter than the set temperature
• You may notice the oven heating beyond the selected temperature before the error appears

Common causes

• Stuck heating relay — the relay on the control board that powers the heating element is stuck in the “on” position, causing continuous heating
• Failed temperature sensor — the sensor reads incorrectly, and the board doesn’t know the oven is overheating until the high-limit thermostat triggers
• Defective high-limit thermostat — the safety thermostat trips prematurely at normal temperatures (false alarm)
• Cooling fan failure — the cooling fan that protects the control board and surrounding cabinetry has stopped working, allowing heat to build up

See all Bosch oven error codes for related fault codes and diagnostic steps.

Troubleshooting steps you can try

1. Turn off the oven immediately — switch off the breaker and let the oven cool completely before any inspection.
2. Wait for cooldown — allow at least 30–60 minutes for the oven to cool before attempting a reset.
3. Power reset — after cooling, restore power and check if the error clears. If it does, monitor closely during the next use.
4. Listen for the cooling fan — when the oven heats, the cooling fan (located behind the back panel) should be audible. No fan noise suggests the fan has failed.
5. Check Bosch support — visit Bosch’s official oven support page for model-specific troubleshooting guides and tech notes.

When to call a technician

ER2 should be taken seriously — an oven that overheats poses a fire risk. A technician will check the heating element relay (a stuck relay is a common failure), test the temperature sensor, verify the cooling fan operates, and test the high-limit thermostat. Do not continue using the oven until the root cause is identified and repaired. Codes may vary by model generation and series. Schedule a certified Bosch technician for fast, reliable diagnosis and repair.