---
title: "Wolf electric cooktop error code U400"
description: "Wolf electric cooktop error code U400: wolf error code U400: the appliance is measuring its own electricity supply and does not like what it sees, on an…"
url: "https://wolfmiami.support/error-codes/error-code-u400-electric-cooktop/"
date_modified: "2026-08-20"
Product line: "CE electric cooktop"
---


# Wolf electric cooktop error code U400

### What this one means

The appliance is measuring its own electricity supply and does not like what it sees, on an electric cooktop, a sealed sheet of glass with the entire control under it. 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.

### 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:

- A supply running high or low at the panel
- A neutral broken somewhere in the house wiring rather than in the appliance
- The two legs of a 240-volt feed not being two separate legs
- Over voltage

### Worth doing before you call

- Take everything off the glass, including a cloth or a hot pan lid over the controls
- Check whether anything else in the house has misbehaved at the same time
- Look at the breaker for this appliance and reset it once

### Then what

This is one of the few codes that is usually about the house and not the machine. An electrician measures the supply; we measure what the appliance did with it.

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

Cooktops & rangetops

What this code means

What this one means

The appliance is measuring its own electricity supply and does not like what it sees, on an electric cooktop, a sealed sheet of glass with the entire control under it. 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.

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:

A supply running high or low at the panel

A neutral broken somewhere in the house wiring rather than in the appliance

The two legs of a 240-volt feed not being two separate legs

Over voltage

Worth doing before you call

Take everything off the glass, including a cloth or a hot pan lid over the controls

Check whether anything else in the house has misbehaved at the same time

Look at the breaker for this appliance and reset it once

Then what

This is one of the few codes that is usually about the house and not the machine. An electrician measures the supply; we measure what the appliance did with it.

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

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**[Read full article: Wolf electric cooktop error code U400](https://wolfmiami.support/error-codes/error-code-u400-electric-cooktop/)**