LG Dishwasher Error Code F-2

The F-2 code means the control board is detecting a temperature of 30 degrees below zero from the thermistor circuit, which is a physically impossible reading under normal conditions. This always points to an electrical fault, specifically an open thermistor circuit rather than an actual temperature problem. The dryer will not function while this code is active.

The dishwasher will not complete a full wash cycle with F-2 active because the dryer function is inoperative without a working thermistor signal. Washing may partially function, but the machine cannot safely or accurately regulate temperature-dependent stages of the cycle. Continued use in this state is not advisable, and the underlying fault should be diagnosed before running additional cycles.

Testing and replacing a thermistor is a manageable DIY repair for anyone comfortable using a multimeter and following a service manual for their specific model. Checking and reseating wiring connectors requires no special tools. Replacing a control board is also a part-swap repair, though it is more expensive if the diagnosis turns out to be wrong, so confirming the thermistor and wiring are both good before ordering a board is strongly recommended.

Start by unplugging the dishwasher and locating the thermistor, which is typically mounted in the wash chamber or on the sump assembly. Inspect the wiring harness and connectors running from the thermistor to the control board for any breaks, corrosion, or loose pins and reseat any suspect connectors. Then use a multimeter to measure resistance across the thermistor terminals; a reading of infinity or far outside the manufacturer's specified range confirms the thermistor has failed and needs replacement. If the wiring and thermistor both test good, the control board is the likely culprit.

If the fix is a loose or corroded connector in the thermistor wiring harness, the repair costs nothing beyond your time. A replacement thermistor sensor is a low-cost part, typically in the range of $15 to $40 depending on the specific LG model. A new wiring harness runs somewhat higher, and a control board replacement is the most expensive path, often $80 to $200 or more for the part alone. A technician's labor for diagnosis and repair typically adds $100 to $200 on top of parts cost.