Viking Designer Cooktop Code FO: Software Error in the Control

What FO means

On Viking Designer DETU series touch-control radiant cooktops, FO is a software error. The cooktop cuts power to each element and puts the code on the timer display. The program inside the control did something unexpected. Letter case matters on these cooktops, and the second character here is a capital letter O, not a zero. Cooking stops until the control starts correctly again.

Common causes of FO

Control software hung or corrupted
Power disturbance during operation
Control board failure

✓ One safe check you can try

1. Turn all controls off and let the glass cool. 2. Switch the breaker off for a full minute and restore power. 3. Press the on key and watch whether the display clears. 4. If FO returns, do not keep cycling power. 5. Call us.

! Why to stop there

Software lives on the control board
Repeated resets will not repair a failing board
A technician can confirm before parts are ordered

Opening a panel yourself does not automatically cancel a manufacturer warranty, but it can cause accidental damage, and some manufacturers set their own service conditions. Check your warranty terms, or ask us, before deciding.

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Other Cooktop codes

FcViking Designer Cooktop Code Fc: Over Temperature With a Small c FdViking Designer Cooktop Code Fd: LED On/Off Test Error 5 flashes (with brief interval)Viking Induction Cooktop Code 5 flashes (with brief interval): Power Device Temperature Sensor FEViking Designer Cooktop Code FE: Temperature Sensor Has Failed 6Viking Induction Cooktop Code 6: filter board error FHViking Designer Cooktop Code FH: EEPROM Control Error on the Board 6 flashes (with brief interval)Viking Rangetop and Cooktop Code 6 flashes (with brief interval): Coil Temperature Sensor Trouble FJViking Designer Cooktop Code FJ: Key Error on the Touch Control

FOFO questions

Is that a letter O or a zero?

It is the capital letter O. The code is FO, a software error. Tell us exactly what you see when you call. It is easy to read the letter O as a zero, so a photo of the display helps.

Can a reset clear it?

Sometimes a power reset restarts the software. If FO comes back, the control board is the likely cause and needs replacing. Cycling power again and again will not help.

Will you give a price first?

Yes. We write the price down before any work, and the repair is covered by our 30-day workmanship warranty. Our technicians also check the supply voltage at the breaker side, so a bad outlet is ruled out first.