Owners of older Professional Series ranges (PDR30/36/48, PRG30/36/48) may see the oven light flash once and the heating light flash twice, repeating. That is code 12, which the legacy service document lists as E4: oven temperature…
Owners of older Professional Series ranges (PDR30/36/48, PRG30/36/48) may see the oven light flash once and the heating light flash twice, repeating. That is code 12, which the legacy service document lists as E4: oven temperature sensor shorted. The control sees an electrical path where none should be, so its temperature reading cannot be trusted. On current Thermador ovens, E4 is a different story.
1. Count the flashes: one, then two. 2. Turn the oven off and give it time to cool. 3. Cycle the range breaker off and on once. 4. If the pattern repeats, stop baking and broiling and schedule service; do not open panels to look for the wire yourself.
E3 reads an open sensor circuit and E4 a shorted one. Both mean the control has lost a believable oven temperature, but they point a technician to different checks.
The control relies on that reading to regulate heat, so we do not recommend using the oven while the pattern shows. Switch it off and call so we can test the sensor circuit.
Just take out racks and cookware once the oven is cool. Leave wiring and panels alone; we handle that part when we arrive and explain what we find.
Our technician checks it in your home and hands you a written price before touching anything.