Dacor Oven Error Code U43

U43 means the upper or single relay board is not detecting a zero crossing signal from the AC power line. Zero crossing detection is required for the relay board to safely time and control the oven's heating elements. The oven will not operate normally until this signal is restored. The fault is typically caused by a loose connection at the S19 connector or a failed relay board.

No, you should not attempt to use the oven while U43 is active. The error indicates the relay board cannot properly control the heating elements, which means the oven may not heat correctly or may not shut off as intended. Discontinue use until the fault is diagnosed and repaired.

If the repair only requires reseating the S19 connector, the cost may be limited to a service call fee, typically in the range of $75 to $150. If the relay board needs to be replaced, parts and labor combined can range from $200 to $500 or more depending on the specific board and local labor rates. Getting a diagnosis from a Dacor-authorized technician will give you a more accurate estimate for your model.

The first diagnostic step, checking and securing the S19 connector, is something a confident DIYer can attempt after unplugging the oven and allowing it to cool completely. However, if that does not resolve the code, replacing the relay board involves working inside the oven's electrical cabinet, which carries serious shock hazards. At that stage, a qualified appliance technician is strongly recommended.

A power reset, such as turning off the circuit breaker for a minute and restoring power, may temporarily clear the displayed code, but it will not fix the underlying problem. If the S19 connection is loose or the relay board is defective, the U43 error will return once the oven attempts to operate again. A reset is not a substitute for proper diagnosis and repair.