---
title: "Bosch error code E12"
description: "Bosch error code E12: limescale has built up in the heat pump. What the code covers, what to check first, and what it does not tell you — on dishwashers."
url: "https://boschmiami.support/error-codes/error-code-e12/"
date_modified: "2026-08-18"
Appliance type: "Dishwashers"
---


# Bosch error code E12

### What this one means

Limescale has built up in the heat pump. It is a code the manufacturer publishes for this appliance, not one we have worked out — and it is decoded here rather than left as three characters on a display.

### The other ways your machine may say it

The same condition is published under more than one label, because it has been carried across generations of this appliance:

- **E12, E2060** — the same condition, on machines of different ages

### What the code covers

A published cause names a circuit rather than a component, which is the single most useful thing to know before ordering a part. This one covers:

- Scale on the heating surfaces inside the pump assembly

### What to try yourself

- Look for a white haze on glassware — the same minerals, showing where you can see them
- Run an empty hot cycle with a proper dishwasher descaler

### Then what

This is the most useful code the machine has, because it arrives long before any damage. South Florida water is hard and this code will come back on a schedule; acting on it is a service, ignoring it for a year is a heat pump.

This code is published for dishwashers. The [full list of codes](https://boschmiami.support/error-codes/) has the rest of them, searchable, including the labels older and newer machines use for the same conditions.

What this code means

What this one means

Limescale has built up in the heat pump. It is a code the manufacturer publishes for this appliance, not one we have worked out — and it is decoded here rather than left as three characters on a display.

The other ways your machine may say it

The same condition is published under more than one label, because it has been carried across generations of this appliance:

E12, E2060 — the same condition, on machines of different ages

What the code covers

A published cause names a circuit rather than a component, which is the single most useful thing to know before ordering a part. This one covers:

Scale on the heating surfaces inside the pump assembly

What to try yourself

Look for a white haze on glassware — the same minerals, showing where you can see them

Run an empty hot cycle with a proper dishwasher descaler

Then what

This is the most useful code the machine has, because it arrives long before any damage. South Florida water is hard and this code will come back on a schedule; acting on it is a service, ignoring it for a year is a heat pump.

This code is published for dishwashers. The full list of codes has the rest of them, searchable, including the labels older and newer machines use for the same conditions.

---

**[Read full article: Bosch error code E12](https://boschmiami.support/error-codes/error-code-e12/)**