What oPn Means
oPn shown together with the word FREEZER means the control is reading the freezer compartment's thermistor as an open circuit. Viking's FDBB5361 service manual (page 40) records a detail worth knowing: if the display happened to be on the other zone when the problem arose, the control switches itself over to the failing zone so the two appear together, and five single beeps accompany the change.
Common Causes of oPn
- Freezer thermistor lead unplugged at the control board
- Harness broken where it passes through the cabinet wall
- Thermistor element failed open
🔧 One Safe Check You Can Try
No homeowner test exists for this. What you can do is watch what the cabinet does rather than what it says, because with the sensor open the control behaves as though the cut-out temperature is never reached and the compartment can run continuously.
⚠ Why You Shouldn't Go Further Than That
- Viking's control keeps running temperature control and defrost while this alarm stands, so the freezer can look healthy for days while one sensor is out of the picture entirely.
- Thermistor resistance is read against a published table that runs from well below zero to room temperature, and without that table a reading is just a number.
- The freezer sensor lead is routed inside the cabinet foam, so pulling on the accessible end to gain slack parts the conductor somewhere it cannot be repaired.
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.