Dacor Range Oven Cooktop Error Code FB

The FB error code on a Dacor Third Generation dishwasher indicates a spray arm diverter fault. The diverter system is responsible for directing water flow between the upper and lower spray arms during the wash cycle. It uses a motorized gearbox to shift water distribution between zones, and position switches confirm that the diverter has moved to the correct location. When the control detects that the position switch is either always closed or always open, regardless of the commanded diverter position, it registers the FB fault and flashes indicators L1 and L6.

The root cause is typically a failure in one of three areas: the gearbox mechanism that physically drives the diverter, the position switches that report diverter location back to the control board, or the wiring harness and connectors that carry signals between those switches and the control. A switch that is stuck closed will always report the diverter as being in one position, while a switch stuck open will appear to the control as if the diverter never moved or never seated properly. Either condition prevents the control from confirming correct diverter operation.

Diagnosis should begin with a physical inspection of the spray arm diverter assembly, checking that the gearbox turns freely without binding and that the diverter physically shifts between positions. The position switches should be tested for continuity in both the open and closed states as the diverter moves. Cables and connectors leading from the switches to the control board should be inspected for corrosion, damage, or loose terminals.