Error code
Bosch error code U400
Bosch error code U400: the supply voltage is outside the range the appliance will run in. What the code covers, what to check first, and what it does not tell you — on cooktops & rangetops and ranges.
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What we can confirm
Code U400, from the manufacturer's own pages
A code is only meaningful together with the generation showing it — the same two digits mean different things across generations.
The code
U400
The supply voltage is outside the range the appliance will run in
or call (305) 783-3552
What it narrows down to
Supply voltage
What you are probably seeing
Diagnostic
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What it looks like from the kitchen
The symptom this code usually arrives with
A code names the subsystem; the symptom is what sent you to look at the display in the first place. That page says what it usually turns out to be, cheapest cause first.
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Sometimes it is the pan Induction cooktop not recognizing the pan
A zone that beeps and gives up, shows a pan symbol, or heats one pan and not another. On induction the cookware is part of the appliance, and a good share of these calls end with a magnet test rather than a repair.
- Beeps and switches off after a few seconds
- Works with one pan, not another
- A pan symbol on the display
In more detail
About Bosch error code U400
What this one means
The supply voltage is outside the range the appliance will run in. 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:
- U400, E9000, E9010 — 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:
- The building's supply
- The circuit feeding the appliance
Worth doing before you call
- Note whether it happens at particular times of day
- Note whether other appliances on the same circuit behave oddly at the same time
Then what
🔴 This is a code about your building, not about your cooktop. No part inside the appliance changes it, and the people to call are the utility or an electrician. Worth establishing before a repair is booked. It is also one of the very few codes that several unrelated manufacturers publish identically, because the induction module underneath is an industry part rather than a brand's own.
This code is published for cooktops & rangetops and ranges. The full list of codes has the rest of them, searchable, including the labels older and newer machines use for the same conditions.
This article is based on:
- Official manufacturer documentation
- Internal repair procedures
- Technician repair history
- Company quality standards