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Daniel, Home Appliance Technician
Category: Appliance
Satisfied Customers: 17410
Experience:  20+ yrs. experience in white goods repair. NVQ Level 2 electronics manufacturers training courses.
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Hi I have a Bosch induction hob that was working with no problems

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Hi I have a Bosch induction hob that was working with no problems three weeks ago
I have been on holiday and when I switched the hob on the code U400 appeared and won't go away
Can you help or is it time for a new one

U400 is a surge on the power boards.

What you can try if you havent already is turn the power supply off for a few hours as this will let the power board drain the electricity out that the capacitors hold.

After a few hours turn it back on and see if this cures it. If it does great fingers crossed this will be fine.

If not then im afraid the power board will be the fault. Now these are very expensive and usually not worth fixing as its not that of the price of a new hob.

But try turning it off at the power supply as you never know this may cure it.

If you need anymore info just get back to me.

Daniel and other Appliance Specialists are ready to help you
Customer: replied 3 years ago.

Thanks for the answer but I already found that out on the net

I thought you might have had some other ideas

Thanks any way


Thats all you can do for this fault. Theres been a power surge and ithas caused the main power board to fail.

So if disconnecting the power hasnt cured it then the board is damaged and needs to be replaced which is as a above usually not worth it as they can be £300+ just for the part only.

As thats what U400 means a power surge on the main contol board.