Microwave displays E2 and stops heating shortly after starting.

Safety warning: Unplug the microwave before removing any panels. Internal components can store dangerous voltage; do not touch the high-voltage section.

Basic checks:

• Allow cooling: If the unit has been used heavily, let it cool for 30–60 minutes, then plug back in and test. Some Commercial Chef models will show E2 if the cavity overheats.
• Check vents: Ensure the top, sides, and rear vents are not blocked by cabinets, walls, or items stacked on top. Poor ventilation can cause overheat errors.
• Clean interior: Heavy food splatter can cause hot spots. Wipe the interior walls and ceiling with a mild detergent and water, then dry thoroughly.

Advanced checks (experienced DIYers):

• Remove the outer cabinet and locate the cavity temperature sensor/thermistor (usually clipped to the top or side of the cavity, with two small wires).
• Disconnect the sensor and measure resistance with a multimeter. Compare to the service manual spec (commonly 10–100 kΩ at room temperature). A reading of 0 Ω (short) or infinite (open) indicates a bad sensor.
• Inspect the wiring harness from the sensor to the control board for pinched or burned wires.
• Replace the sensor if out of spec, reassemble, and test.

Note: If the sensor and wiring are good, the control board's temperature circuit may be defective and should be replaced by a professional.