Bosch dishwasher E12 code
E12 is listed by Bosch support as limescale buildup in the heat pump. The exact checks and component layout can vary by model and region.
Limescale buildup in the heat pump
Switch the dishwasher off before cleaning user-accessible parts. Hidden glass may be present near the filter and pump cover.
Typical symptoms
Likely causes
Start with the least invasive explanation and stop if the check requires internal electrical or sealed-system access.
Safe next steps
- 1Empty the dishwasher and remove loose food debris from the filter
Follow the exact model manual where access or reset steps differ by product series.
- 2Use one Bosch-approved dishwasher descaler, following the dosage and cycle printed on its package
Follow the exact model manual where access or reset steps differ by product series.
- 3Run the descaling cycle without dishes or detergent
Follow the exact model manual where access or reset steps differ by product series.
- 4If the model has a water softener, refill dishwasher salt and confirm the hardness setting in the owner manual
Follow the exact model manual where access or reset steps differ by product series.
- 5If E12 returns after descaling, arrange Bosch service because limescale may remain in the heat pump
Follow the exact model manual where access or reset steps differ by product series.
When to stop
Stop if you see damaged wiring, smell burning, find an active leak, suspect gas or refrigerant, or need to remove a sealed electrical cover. Use a qualified appliance technician.