Symptoms
• Dryer stops mid-cycle and displays F04 error code on the control panel
• Dryer refuses to start when F04 is shown
• Clothes remain damp even after running a full cycle
• Drum rotates but heat does not turn on
• Control panel may beep or flash when attempting to start the dryer
• Error code persists after power cycling the unit
Possible Causes
• Moisture sensor contacts are dirty, corroded, or obstructed by lint buildup
• Loose or disconnected wiring harness connected to the moisture sensor
• Faulty moisture sensor that has failed electrically
• Control board issue preventing proper sensor signal communication
• Lint or debris accumulated inside the sensor housing
• Poor electrical connection at the sensor terminals due to corrosion or wear
Safety Checks You Can Do
• Unplug the dryer from the 240V outlet for 5 minutes, then plug it back in to reset the control board and clear temporary error codes
• Check that the dryer is properly connected to a grounded 240V/60Hz circuit and that the circuit breaker has not tripped
• Open the dryer door and visually inspect the moisture sensor (typically a small probe-like component inside the drum) for visible lint, dust, or debris
• Use a soft, dry cloth or small brush to gently clean any lint from the moisture sensor contacts if they are accessible without disassembly
• Verify that the exhaust vent duct is not blocked and air flows freely from the back of the dryer outside (check both the duct and external vent hood)
• Remove and clean the lint filter thoroughly, then run a short test cycle to see if the error clears
• Ensure the dryer is level and not tilted, as this can affect sensor operation
• Check that no moisture, water, or liquid has contacted the control panel area
Safety First
Always disconnect the appliance from power before performing any checks. If you are unsure about any step, please contact a qualified technician.