Whirlpool Dryer Error Code f:20

F:20 means the electronic control board detected no voltage at the heater relay while running in Diagnostic Test Mode. This code only appears during diagnostics, not during a regular drying cycle. The most likely causes are loose wire connections at the heater element or at the heater relay on the control board.

F:20 only appears in Diagnostic Test Mode, so your dryer may still run a drying cycle. However, if the heater circuit has a wiring fault, the dryer may run without producing heat, leaving clothes damp. Running the dryer without resolving the fault does not pose an immediate safety risk, but the underlying wiring issue should be addressed to ensure the heating system operates correctly.

The first step, checking wire connections at the heater element and control board relay, is accessible to most homeowners with basic tools. Unplug the dryer, remove the back panel to reach the heater element connections, and check the control board harness connectors. Tracing a broken wire in the harness requires a multimeter and some familiarity with reading wiring diagrams. Replacing the control board is a moderate DIY repair. If you are not comfortable working around appliance wiring, a certified technician can complete this diagnosis quickly.

Start by unplugging the dryer and inspecting the wire connectors at the heater element and at the heater relay on the electronic control board. Press each connector firmly to ensure it is fully seated. Reconnect power, re-run Diagnostic Test Mode, and check whether F:20 returns. If it does, inspect the wiring harness for breaks or burns. If the harness is intact, the heater relay on the control board has likely failed and the board will need to be replaced.

If the fix is simply reseating a loose wire connector, there is no parts cost and the repair takes only a few minutes. If the wiring harness is damaged, a replacement harness typically costs between $20 and $60 in parts. A failed electronic control board is the most expensive scenario, with parts ranging from $100 to $250 depending on the model. Labor for a technician runs roughly $75 to $150 per hour if you choose not to do this repair yourself.