How to Fix Bosch Dishwasher Error E12

Error Code: E12 Difficulty: Easy

Problem: Limescale build-up in the heat pump.

How to Fix E12 Error (Step-by-Step)

1. Run a cleaning cycle with a dishwasher-specific descaling product and confirm the error stays cleared during a full test cycle.
2. Pour the descaler directly into the bottom of the empty dishwasher.
3. Select the hottest and longest wash cycle available on your dishwasher.
4. Allow the cycle to run completely without interruption and confirm the error stays cleared during a full test cycle.
5. For heavy buildup, a second treatment may be necessary and confirm the error stays cleared during a full test cycle.
6. Regularly use a descaler every 1-3 months to prevent future limescale accumulation.
7. Ensure your water softener (if you have one) is functioning correctly and filled with salt.
8. Turn the appliance off, wait about 2 minutes, then turn it back on.

Still Not Working?
If the replacement part didn’t fix the issue, you may have a wiring problem or main board failure.