What E4 Means
E4 is the lower compartment thermistor sensor error - the lower zone's sensor reading open or out of range. Viking's VUWC244DRSS service manual (2010, page 24) gives it the same three causes as the upper zone: a disconnected or broken wire, shorted thermistor wires, and a failing thermistor.
Common Causes of E4
- Sensor wire disconnected or broken
- Thermistor wires shorted together
- Thermistor itself has failed
🔧 One Safe Check You Can Try
Start with the power-on reset Viking prescribes for all E# codes on this cabinet. If E4 comes back once power has been restored and the control has settled, the lower sensor or its wiring needs attention rather than another reset.
⚠ Why You Shouldn't Go Further Than That
- The lower compartment sits closest to the machine compartment, so a lower-zone complaint can equally come from condenser airflow, and only testing tells you which.
- Viking's diagnostics mode reports the lower thermistor as test number 1, with its own OK, open and shorted indications - a sequence a technician enters rather than something visible at the panel.
- Replacing a sensor without finding a chafed wire puts a new part onto the same break.
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.