Medium - Inspection Needed

Thermador Cooktop U400 Error Code

Documented on both platforms, identically to E9000/E9010, as the supply voltage being outside the cooktop's normal operating range.

What U400 Means

Documented on both platforms, identically to E9000/E9010, as the supply voltage being outside the cooktop's normal operating range.

Common Causes of U400

  • A home electrical supply voltage issue
  • An incorrectly wired circuit for the cooktop

🔧 One Safe Check You Can Try

This points to the incoming electrical supply, not something to troubleshoot at the cooktop.

⚠ Why You Shouldn't Go Further Than That

  • Confirming supply voltage requires an electrician or the utility provider, not appliance-side repair.

Opening a panel to inspect or repair something yourself doesn't automatically cancel your manufacturer's warranty — but it can risk accidental damage, and some manufacturers do have specific service conditions. Check your product's warranty terms, or ask us, before deciding.

Other Cooktop Error Codes

Related Guides

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FAQ

U400 FAQ

Thermador documents both under the same voltage-out-of-range description; which one displays can depend on the exact control platform.

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