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Bosch Dishwasher E12 Error Code

Limescale buildup in the heat pump. What it means, which models show it, and how to clear it, easiest fix first.

BoschAll Bosch dishwasher codes

E12
Easy DIY fix

Hard-water scale has built up in the heat pump, the part that heats and moves the wash water. It is most common in hard-water areas, or where the built-in water softener isn't kept supplied with salt.

Compatible models

Bosch doesn't publish a model list for this code; it appears on Bosch dishwashers with a digital display. Check your owner's manual.

Also shown as

Newer US models show E2060. Models with a built-in water softener (common in the UK and EU, also on some US models) rely on dishwasher salt to prevent this.

Difficulty

Most people can clear this one at home with simple checks.

Safety first: unplug the dishwasher (or switch off its breaker) before touching filters, hoses or panels. If you smell burning or gas, or see water near the outlet, stop and call a professional.

How to fix Bosch E12

  1. Run a descaling cycle

    Use a dishwasher descaler, such as Bosch's own, and follow the directions on the pack. Run it with the dishwasher empty.

  2. Top up the softener salt

    If your dishwasher has a salt reservoir, fill it with dishwasher salt (not table salt) and set the water hardness in the settings to match your area. This slows down scale coming back.

  3. Reset the dishwasher at the breaker

    Switch off the dishwasher's circuit breaker, wait about 30 seconds, then switch it back on. Run a short cycle with the dishwasher empty and watch whether the same code comes back. A code that clears and stays away was likely a one-time glitch.

When to call a technician

If E12 keeps returning after descaling, contact Bosch support. The heat pump may be heavily scaled or failing.

Parts linked to E12

These are the parts most often behind this code. Tap one to see what it does and the signs it is failing.

Order parts by your full model number so they fit.

Frequently asked questions

What does E12 mean on a Bosch dishwasher?

Hard-water scale has built up in the heat pump, the part that heats and moves the wash water. It is most common in hard-water areas, or where the built-in water softener isn't kept supplied with salt.

Which Bosch models show the E12 code?

Bosch doesn't publish a model list for this code; it appears on Bosch dishwashers with a digital display. Check your owner's manual.

Can I fix Bosch E12 myself?

Usually, yes. Most E12 problems clear with simple checks you can do at home. Start with the first step above: run a descaling cycle.

What if E12 keeps coming back?

A code that returns after a reset and the checks above usually means a part is wearing out. Note when E12 appears (which cycle, how often) and have your model number ready; it helps a technician bring the right part on the first visit.

Other Bosch dishwasher codes

Last reviewed 2026-10-19. Codes and steps can vary by model; check your owner's manual.

Sources we checked