F6/E4 points to a mismatch between the user interface (UI/touch panel) and the electronic oven control (EOC). The error usually appears right after a repair when someone installed an incompatible UI or control board.
What the Error Means
Your oven’s UI and EOC must share the same firmware family and part compatibility. If they don’t “speak” the same language, the control logic blocks operation and throws F6/E4.
When You’ll See It
Most cases occur immediately after parts replacement—power up, beep, then F6/E4. Normal functions won’t start because the boards can’t hand-shake.
How to Diagnose
Confirm whether the UI or the EOC was recently replaced. Check the model/serial tag and the exact part numbers on the invoice or the boards themselves, then verify compatibility in the parts catalog or service sheet for your model. If the oven worked before the last repair and now shows F6/E4, the new part is likely the mismatch.
The Fix
Install the correct, compatible component—either the proper UI/console or the correct EOC—so both modules match your oven’s model and revision. After replacement, power-cycle the unit, clear stored codes per the service sheet, and verify normal key response, relay operation, and accurate preheat.
Why Professional Service Helps
Matching UI and EOC parts isn’t just about physical fit; firmware and revision codes matter. A qualified technician can identify the wrong part quickly, source the right revision, handle fragile ribbon cables, and confirm the repair with post-install checks.
Prevention & Notes
Keep the model and serial numbers with your records before any repair. When ordering parts, specify the full model string and revision to avoid cross-family substitutions. After service, test the console and run a short bake to ensure the error does not return.