Safety first: Turn off power at the mains and allow the oven to cool fully before working on it.

Steps to check:

Visual inspection: Remove the rear cover and inspect the sensor wiring for melted insulation or contact with metal chassis.
Resistance test: Disconnect the sensor and measure resistance. A very low reading (near 0 Ω) indicates a shorted sensor.
Check for moisture: Inspect the sensor connector and control board area for signs of moisture or steam damage. Dry thoroughly and correct any sealing issues around the cavity.
Isolate short: If the harness is shorted to the chassis, reroute or replace the wiring harness and secure it with clips away from hot or sharp areas.
Replace sensor: Install a new sensor if the original is shorted. Clear the error by disconnecting power for several minutes and retesting.
Control board evaluation: If a new sensor and harness do not resolve E3, the control board may be misreading temperature and should be replaced by a professional.

E3 error appears and oven overheats or burns food quickly.

Possible Causes