AGA Error Code U400
The range has been incorrectly connected (supply wiring fault) — what this fault code means on AGA induction hob / range error codes, and how we fix it.
- Fault code
- AGA induction hob / range error codes
- Installation
Meaning
What code U400 means
The range has been incorrectly connected (supply wiring fault)
Coverage
Which models show it
- AEL361IN
- AEL481IN
- AMC36IN
- AMC48IN
- AMPRO36IN
- AEL36INRT
- AEL48INRT
- AMC36INRT
- AMC48INRT
- AGA ERA induction
The fix
How it is fixed
The control switches off after approximately 1 second and the code is permanently displayed. Consult the installer or a qualified engineer and correct the mains connection.
Safety & DIY disclaimer
Guides on this site are for information only. Appliance repair involves 240V electricity, gas connections, refrigerant and heavy cast-iron parts — anything you do yourself is at your own risk and can damage the appliance or cause injury. The safe option is to book a qualified technician.
Symptoms
Problems linked to this code
AGA induction hob / range error codes
More codes on this platform
Frequently asked questions
What does AGA error code U400 mean?
The range has been incorrectly connected (supply wiring fault)
Can I keep using my AGA with code U400?
A power cycle at the breaker (60 seconds) may clear a one-off code. If the code returns, stop using the affected zone or appliance and book service — continuing to run can turn a small fault into a board-level repair.
AGA showing code U400?
We read AGA fault logs with factory-level tools — no guesswork. Diagnostic fee applies toward your repair.
Mon–Sun 8:00AM–8:00PM
Independent service company — not affiliated with or authorized by AGA / AGA Rangemaster (Middleby). We repair out-of-warranty AGA appliances.