On a Viking DFUD, F3 flags the temperature thermistor; the wash skips heating and carries on.
Model compatibility: Viking reuses codes across series and model years, so F3 / L3 may mean something different on another appliance or generation. Confirm this against your model’s documentation and record your full model number before acting.
Plain language
What this code means
F3 means the thermistor is interrupted or above 176F, and the program leaves the heating stage and continues; it shows only in the service menu.
Viking’s DFUD dishwasher service manual defines F3, shown as L3 on LED models, as a thermistor fault. The thermistor is the small sensor that reports the water temperature to the control, and the manual names two failure conditions: an open circuit, or a reading above 176F.
What the machine does
With an interrupted thermistor the control receives no temperature at all, and a value over 176F is beyond anything the cycle should produce. The manual treats both as the same fault. Because the water temperature cannot be trusted, the control does not run heating:
the program leaves the heating stage;
the remaining stages continue;
the fault is indicated in the service menu only.
Items on the manual’s list
Two entries: the thermistor, and the control unit, which takes in its signal.
Handling it at home
The manual offers no owner steps for F3, and nothing in it suggests a repair at home. Water this hot can scald, and because the sensor connects to the control, any panel comes off only after the power is disconnected. When you call, report the code and mention that the cycle ran without a heating stage.
Codes to compare
F1 covers water that heats too slowly, with the heating element and circulation among its checks.
4-1 reports a temperature sensor problem on dishwashers of the newer flash-count design.
Viking dishwasher service in Los Angeles
Technicians handle Viking dishwasher F3 faults across Los Angeles; reach the team on (310) 692-1112. Have the model number from the rating plate and the code ready. More on the dishwasher service page.
Important safety warning. Do not attempt repairs involving electrical components, gas, water lines, refrigerant or sealed systems. Unplug the appliance if it is safe to reach the outlet, and leave internal diagnostics to a qualified technician.
Seeing this code on your Viking appliance?
Book a specialist visit for a clear estimate and approval before any repair.
