LG Dishwasher Error Code F-9

F-9 means the dishwasher's control board has detected incoming supply voltage below 90 volts AC. This is a low voltage fault specific to the electrical circuit the dishwasher is connected to. Unlike most error codes, F-9 does not appear on the display automatically and must be retrieved manually by pressing and holding the OFF pad, then pressing and holding PAUSE/RESUME for two seconds.

The dishwasher will continue to run with this fault active, but operating consistently below 90 volts is not safe for the appliance long-term. Low voltage forces motors and heating elements to draw higher current to compensate, which generates excess heat and accelerates wear. You should address the electrical supply issue before continuing regular use.

F-9 is a hidden fault that does not interrupt operation or trigger a visible alert during normal use. The dishwasher stores the code internally and continues running, which is why you may not notice any immediate problem. Over time, sustained low voltage causes poor cleaning performance, longer cycle times, and premature motor failure, so the absence of obvious symptoms does not mean the condition is harmless.

Press and hold the OFF pad, then while keeping it held, press and hold the PAUSE/RESUME pad for two seconds. The control board will display any stored fault codes, including F-9. The code is stored in memory even though it does not show during normal operation.

If the problem is a loose wire connection at the outlet or junction box, the fix costs nothing beyond your time. Replacing a standard wall outlet runs $5 to $20 in parts. If the circuit is overloaded and needs to be dedicated or upgraded, an electrician typically charges $150 to $300 for that work. If low utility voltage is the cause, contact your power company, as correction is their responsibility and typically no cost to you.