What 1620 Means
The auxiliary double line break relay reading open when the control expected it closed. Wolf's M Series Troubleshooting Manual lists 1620 at priority 2. Because the auxiliary bank feeds the oven's secondary loads, an open auxiliary DLB typically takes out several smaller functions at once rather than the main heating.
Common Causes of 1620
- Auxiliary DLB relay contacts no longer closing
- A driver problem on the relay board leaving the auxiliary bank uncommanded
- A connection problem in the auxiliary bank wiring
🔧 One Safe Check You Can Try
Make a list of what has actually stopped working - lights, fans, lock - and what still works. A group of secondary functions failing together is the signature of a bank-level problem rather than a single part.
⚠ Why You Shouldn't Go Further Than That
- The auxiliary bank is part of the oven's line-voltage disconnect arrangement, which is not a circuit to open up at home.
- Several secondary loads failing together looks like several problems, and replacing them one by one is a slow and costly path to a single relay.
- The relay board carries the heating circuits as well, so board-level access belongs with a technician.
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.