The display shows E12 and the cycle may stall or finish with poor heating. Thermador documents this code as limescale build-up in the heat pump. The machine has noticed that mineral deposits are getting in the…
The display shows E12 and the cycle may stall or finish with poor heating. Thermador documents this code as limescale build-up in the heat pump. The machine has noticed that mineral deposits are getting in the way of normal heat transfer. It is treated as a maintenance code, which is why its severity here is low.
1. Pick a descaling product made for dishwashers and read its label. 2. Empty both racks and the filter area, then run the descaler through a full cycle as the label directs. 3. If your model uses water-softening salt, check the salt compartment and top it up. 4. Run a normal cycle afterward and see whether E12 returns.
It depends on how hard your water is. Harder water calls for shorter gaps between treatments, and your manual lists the recommended interval for your model.
Usually not. It reads as a maintenance reminder, but ignoring it can mean weaker heating and drying over time, so schedule the descale or a visit rather than waiting for it to get worse.
On models that use softening salt, an empty compartment lets more scale reach the heat pump. Keeping it filled is a simple way to slow the build-up that produces E12.
Our technician checks it in your home and hands you a written price before touching anything.