Amana Microwave Error Code E21

E21 indicates a thermal sensor open circuit error. The microwave's control board is not receiving a valid signal from the cavity temperature sensor, which suggests the sensor itself, its wiring, or the connection to the PCB has failed. The microwave shuts down to prevent unsafe operation without temperature monitoring.

No. The E21 code causes the microwave to stop operating specifically because it cannot monitor internal temperature. Continuing to use it without a functioning thermal sensor could result in overheating or damage to internal components. The microwave should remain out of service until the fault is diagnosed and repaired.

Repair costs vary depending on the root cause. A replacement thermal sensor typically runs in the range of $10 to $40 for the part alone. If a new control board is needed, parts can range from $80 to $200 or more. Adding professional labor, total repair costs generally fall between $75 and $250 depending on what components require replacement.

Some causes are DIY-friendly, such as reseating a loose connector or inspecting wiring for visible damage. However, working inside a microwave involves high-voltage components, including the capacitor, which can retain a lethal charge even when unplugged. If you are not experienced with high-voltage appliance repair, this job is best left to a qualified technician.

Unplugging the microwave for a short time may temporarily clear the error, but it will return as soon as the control board detects the open sensor circuit again during startup or operation. A reset does not fix the underlying hardware fault, so the sensor, wiring, and connections must be inspected and repaired.