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ERROR CODEE12Diagnostic reference

Bosch · Dishwashers

Bosch Dishwasher E12: Limescale in the Heat Pump

Documentation checkedBy ErrHiveUpdated

THE SHORT ANSWER

Limescale has built up in the heat-pump area.

Bosch identifies E12 as limescale buildup and recommends dishwasher descaling. Follow the descaler and model instructions rather than opening the heat pump.

First safe check

Check your model's descaling instructions and use a product suitable for the dishwasher.

Applies to

Bosch US dishwasher support; match the complete display to the model documentation.

Before you start

Do not mix cleaners or access the heater. Use the appliance and cleaning-product instructions.

Go to safe checks

WHAT YOU MAY NOTICE

Symptoms to record

  • The display shows E12.

WORK THROUGH THE BASICS

Safe troubleshooting checks

0 of 2 checked

Use the checkboxes to keep track as you read. Stop at any warning or step that does not match your appliance.

  1. Use the documented dishwasher-descaling procedure and product directions.

    What to note

    Scale treatment is performed without dismantling the appliance.

  2. If your model has a water softener, check its salt-care instructions.

    What to note

    The model's existing softener can be maintained correctly.

THE DETAILS MATTER

Scope & troubleshooting notes

How to use this guidance

Softening salt is relevant only to models equipped for it. Do not put salt into an arbitrary compartment or substitute an improvised chemical mixture. Report a returning E12 after documented care to Bosch.

YOUR NEXT DECISION

When to stop and get help

If the message persists after the documented owner checks, contact Bosch support with the complete display and model number.

Record what you see

Keep the full model number, exact displayed code, and your observations together for the next conversation.

Use the right support

Contact the manufacturer or a qualified appliance technician when the guide calls for service.

Bosch support

THE EVIDENCE

Sources & verification

Our explanations are editorial summaries of the documentation below. They do not replace the instructions for your exact appliance.

  1. E12 Bosch Dishwasher Error Code

    Bosch Home Appliances · Manufacturer support · Checked

    Meaning and owner guidance — Bosch US dishwasher support; match the complete display to the model documentation.

ErrHive is an independent information resource, not an authorized representative of Bosch. Follow your appliance’s manual. Hazardous repairs belong with qualified professionals. Read our safety policy.