Dacor Range Oven Cooktop Error Code U54

Error code U54 on a Dacor range or oven indicates a fault in the door latch system for the upper or single oven cavity, specifically traced to a bad relay board. The relay board is responsible for controlling the latch motor that locks and unlocks the oven door during self-clean cycles and high-temperature operations. When the relay board fails or produces incorrect output signals, the control system cannot properly command the latch mechanism, triggering this fault code.

The relay board contains electromechanical or solid-state relays that switch higher current loads to components like the latch motor. A failed relay on this board can result in the latch motor receiving no power, incorrect voltage, or intermittent signals. This prevents the latch from completing its travel to a fully locked or fully unlocked position, which the oven's control board detects as a fault condition. In some cases, a relay contact may be welded closed or burned open due to heat exposure or electrical stress over time.

Diagnosing U54 requires inspecting the relay board for visible signs of damage such as burnt relay contacts, scorched PCB traces, or swollen components. Technicians should also verify that wiring harness connections between the relay board and the latch motor are secure and undamaged before condemning the board itself. If the wiring is intact and the latch motor tests within specification, the relay board is the likely root cause and will need replacement to restore normal door latch operation.