Dacor Range, Oven, Cooktop Error Code F90

F90 on a Dacor Discovery Range indicates a Key Loop Detect Failure. This means the control board has detected a problem with the signal circuit that runs between the relay board and the control panel. The fault is caused by either a loose or damaged data cable or a defective membrane switch assembly. The range will not operate normally until the underlying wiring or component issue is corrected.

An F90 fault typically means the control panel is not communicating correctly with the relay board, which can prevent the range from accepting input commands reliably. Continuing to use the appliance in this condition is not recommended, as control behavior may be unpredictable. Disconnect power until the fault is diagnosed and repaired.

If only the data cable needs to be reseated, there may be no parts cost involved, though a service call fee from a technician would still apply if you hire one. Replacing the data cable or the membrane switch assembly typically runs in the range of $100 to $350 for parts depending on the specific model, plus labor costs if a technician performs the work. Relay board replacement, if needed, can bring the total cost higher.

The first step is to check the data cable connections between the relay board and the control panel, which is a task many experienced DIYers can handle after disconnecting power to the unit. If reseating the cable does not clear the fault, replacing the membrane or the cable requires sourcing the correct replacement part and disassembling the control panel area. If you are not comfortable working inside the appliance, a qualified technician should perform the repair.

A power reset by unplugging the range or switching off the circuit breaker for several minutes may temporarily clear the F90 code, but it will return if the underlying hardware fault is not repaired. A loose cable that reseats itself during handling might appear resolved after a reset, but the fault will likely recur with use. Physically inspecting and securing the data cable is necessary to confirm the repair.