F21 flags a shorted or stuck key on a Viking TOD2 control and cancels timed cooking.
Model compatibility: Viking reuses codes across series and model years, so F21 may mean something different on another appliance or generation. Confirm this against your model’s documentation and record your full model number before acting.
Plain language
What this code means
The TOD2 detects one or more keys shorted for longer than 1 minute and cancels any timed cycle or delay start.
What the TOD2 saw
F21 is shown when the TOD2 control reads one or more keys as shorted for longer than one minute, as though the key were being held down.
Effect
The EOC4 sheet rates it priority B, non-critical: just the affected feature is dropped, and the oven stays usable.
Timed cycles and delay start are what get cancelled.
The code appears on wall ovens with a TOD2 or TOD3 clock. No flashing-light pattern is listed in the table.
Observations worth noting
Any pad that seems wedged or depressed; inspect it without prying.
If the code comes straight back once cleared, or only following one particular key.
If timed and delayed settings are refused while ordinary baking carries on.
Remedy from the sheet
The listed action is to replace the TOD2 or fix the problem. Wiping near the keypad while the oven is off is harmless; keep sprays and liquids away from the panel.
Related codes
F7: a shorted input key on ERC-controlled wall ovens.
If F21 is persistent, call (310) 692-1112 and have the model number and the time the code first came up. We cover Viking ovens in Los Angeles, as listed on the oven repair page.
Important safety warning. Do not attempt repairs involving electrical components, gas, water lines, refrigerant or sealed systems. Unplug the appliance if it is safe to reach the outlet, and leave internal diagnostics to a qualified technician.
Seeing this code on your Viking appliance?
Book a specialist visit for a clear estimate and approval before any repair.
