What 1C21 Means
Not one disconnect relay open but both of them on the upper cavity's bake bank. Wolf's M Series Troubleshooting Manual lists 1C21 at priority 2, with matching codes for the broil bank and the lower cavity. Both legs of the bake supply are reading disconnected, so there is no path to the bake element at all.
Common Causes of 1C21
- A relay board driver problem leaving the whole bake bank uncommanded
- A supply problem to the bake bank on the relay board
- Both DLB relays having genuinely failed open, which usually points upstream rather than to coincidence
🔧 One Safe Check You Can Try
Confirm the scope of the problem: does the upper cavity heat on any function, and does the lower cavity behave normally? Both answers matter, because a problem that takes out both DLBs on one bank behaves differently from a whole-oven failure.
⚠ Why You Shouldn't Go Further Than That
- Two relays failing at once rarely means two failed relays, so replacing them is likely to be treating a sign rather than the cause.
- The DLB arrangement is the oven's line-voltage disconnect, and board-level work there is not a homeowner task.
- An oven with a whole heating bank offline should be diagnosed from the problem log rather than by swapping the most accessible part.
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.