Whirlpool Dryer Error Code F-21

F-21 indicates a failure detected in Heater #2, the second heating element on dual-element electric dryer models. The control board monitors the heater circuit and triggers this code when it cannot confirm that the element is operating correctly. This code only applies to electric dryers with dual-element heating systems. Gas dryer models will not display this fault.

Running the dryer with an active F-21 fault is not recommended. With one heater element out of service, drying performance will be reduced and the underlying cause of the failure, such as restricted airflow leading to overheating, could pose a risk if left unaddressed. It is best to diagnose and correct the fault before continuing regular use.

Resetting the dryer by unplugging it or cycling power may temporarily clear the code from the display, but the fault will return if the underlying component failure has not been fixed. The control board will detect the same heater circuit problem as soon as the dryer attempts to heat again. A proper repair requires identifying and replacing the failed component in the Heater #2 circuit.

A knowledgeable DIYer with a multimeter can diagnose this fault by testing the heating element, thermal fuse, and high-limit thermostat for continuity following the TEST #4 heater diagnostic procedure. Replacing a burned-out element or blown thermal fuse is a moderately involved repair that requires disconnecting power and accessing internal components. If you are not comfortable working inside an electric dryer, a qualified technician should perform the repair.

Repair costs depend on which component has failed. A replacement thermal fuse is typically an inexpensive part, often in the range of $5 to $20, while a new heating element can run anywhere from $30 to $100 or more depending on the model. Adding professional labor, total repair costs commonly fall between $100 and $300. Diagnosing the exact failed component first helps avoid unnecessary parts purchases.