Written by
Lena Hartwell Appliance Care EditorPublished October 27, 2026
VERIFIED
Error codeU43 / L43
ApplianceWall Oven
The signal that went missing
U43 turns up on an upper or single oven and L43 on a lower oven. Both state that the zero-cross (ZC) signal on the upper board is gone. According to the manual, the error can be reversed.
Two possible causes
A bad connection on S19, the double line break relay
A bad relay board
Technician procedure
Verify the connections at S19.
Secure them.
If the code persists, replace the relay board.
While it is active
No functions are available, so the oven neither cooks nor self-cleans. Call for service.
Scope
This comes from the Dacor manual for single and double wall ovens, 27 and 30 inches, with touch-glass control. No series is named.
Bay Area owners with U43 or L43 can book at (415) 687-5926. Keep the displayed code, the model number and any steps you took before calling. Browse Dacor wall oven repair as well.
Model compatibility: Dacor reuses codes across series and model years, so U43 / L43 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
No zero-cross (ZC) signal seen on the relay board; the error is reversible.
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 Dacor appliance?
Book a specialist visit for a clear estimate and approval before any repair.
You submit a request with your appliance model and symptom, we confirm an appointment window, and a technician performs an on-site diagnosis. You then receive a clear estimate and decide whether to proceed before any repair begins.
Yes. We provide an upfront estimate after diagnosis. No parts are ordered or installed until you approve the work, so there are no surprise charges.
Replacement parts are selected for the exact model and confirmed with you before ordering or installation.
Service areas are listed on the Locations page. Contact us with your ZIP code to confirm current coverage for your address.
Ready to get your Dacor appliance working again?
Book a repair online or call us — clear estimates and approval before any repair work begins.
