Amana Microwave Error Code 21

Code 21 is a service code indicating that the microwave has detected a temperature condition that is too low for normal operation. It is typically triggered by cold ambient room temperatures rather than a mechanical failure. The unit's control board monitors temperature and displays this code as a warning when readings fall below the acceptable threshold.

Code 21 indicates the microwave is operating outside its recommended temperature range, so it is best to avoid using the unit until the issue is resolved. Operating in very cold conditions can affect performance and potentially cause other issues. Address the temperature condition first before resuming normal use.

If the issue is simply a cold room, there is no repair cost involved. If a temperature sensor needs to be replaced, parts and labor costs can range from around $75 to $200 depending on the specific sensor and service rates in your area. A control board replacement, if required, would typically be at the higher end of the cost range or may make repair less economical depending on the age of the unit.

Start by checking the temperature of the room where the microwave is located. If the space is cold, move the microwave to a warmer area or heat the room and allow the unit to acclimate for at least 30 to 60 minutes. If the code persists in a normal-temperature environment, the temperature sensor or its wiring should be inspected for faults.

A simple reset by unplugging the microwave for a few minutes may temporarily clear the display, but the code will return if the underlying condition, such as low room temperature or a faulty sensor, has not been corrected. Addressing the root cause is necessary for a lasting fix.