Electrolux Microwave Error Code E-21

E-21 indicates that the control board has detected an open circuit in the thermal sensor. The thermal sensor monitors temperature inside the microwave, and when the circuit through it reads as broken or has infinite resistance, the E-21 code is triggered. The microwave typically stops operating until the fault is resolved to prevent unsafe conditions from undetected overheating.

No, you should not continue using the microwave while E-21 is active. The thermal sensor is a safety component that prevents dangerous overheating, and operating the unit without a functioning sensor removes that protection. Most Electrolux microwaves will disable operation automatically when this fault is detected, but if yours does not, stop using it until the sensor is repaired.

Repair costs vary depending on whether the issue is a simple connector problem or a full sensor replacement. A thermal sensor part typically costs in the range of $15 to $50, while professional labor to diagnose and replace the component can bring the total repair cost to roughly $80 to $200 depending on the service provider and your location. If the wiring harness also requires replacement, costs may be higher.

A knowledgeable DIYer can begin by inspecting the thermal sensor wiring and connectors for obvious damage and reseating any loose connections. Testing the sensor itself requires a multimeter to check for continuity across its terminals. However, working inside a microwave involves high-voltage components including the capacitor, which can retain a dangerous charge even when unplugged, so this repair is generally recommended for experienced technicians.

A power reset by unplugging the microwave for a few minutes may temporarily clear the code, but E-21 will return if the underlying open circuit in the thermal sensor has not been repaired. The fault is hardware-based, meaning the control board will detect the open sensor again as soon as it attempts to read it. A proper repair of the sensor or its wiring is required for a lasting fix.