Lennox EL296UHV Error Code E 310: Discharge Error Temperature Sensor Failure
What Does Code E 310 Mean?
Error code E310 on the Lennox EL296UHV indicates that the discharge air temperature sensor has failed. The sensor is either shorted or reading a value outside the expected range. This sensor measures the temperature of the air leaving the furnace and entering the ductwork.
The control board uses discharge temperature data to monitor furnace performance and detect conditions like restricted airflow or excessive heat. Without a functioning sensor, the board loses this monitoring capability. The furnace will still heat, but it cannot perform temperature-based safety checks or performance adjustments that rely on this sensor.
In communicating mode, the error clears 30 seconds after the sensor fault recovers. In non-communicating mode, it clears after the current heat call is completed. A technician should compare the sensor's resistance to the temperature/resistance chart in the installation instructions and replace the sensor if it is out of specification.
When to Call a Professional
Contact a licensed HVAC technician if:
- The discharge temperature sensor needs to be tested and replaced
- You want to restore the furnace's ability to monitor supply air temperature
- E310 appears alongside temperature-related codes like E252 or E311
✓ Verified against manufacturer service manual — March 2026