Oven overheats or shuts down with E03 displayed; may smell very hot or scorch food quickly.

Safety: If the oven is overheating, turn off the breaker immediately and allow the unit to cool completely before inspection.

• Visual check: After cooling, inspect the interior for warped racks, discolored liner, or signs of extreme heat. Do not use the oven until the cause is identified.
• Test the temperature sensor: With power off, access the sensor at the rear wall. Remove and measure resistance at room temperature. A reading much lower than 1000 Ω (indicating a short) can cause overheating; replace the sensor.
• Inspect wiring: Check the sensor harness for bare spots or contact with metal surfaces that could cause a short. Repair or replace damaged wiring.
• Check high-limit thermostat (if accessible): Some Sub-Zero ovens have a high-limit thermostat or thermal cutoff behind the rear panel or above the cavity. Inspect for signs of overheating or discoloration. If the thermostat is welded closed or the thermal fuse is bypassed, replace with the correct OEM part.
• Control board relays: If the sensor and wiring are good, the bake or broil relay on the control board may be stuck closed, continuously powering the element. This requires control board replacement and should be done by a qualified technician.
• Do not bypass safety devices: Never bypass thermal cutoffs or thermostats; they are critical safety components.