Lennox EL296UHV Error Code U: Discharge Air Temperature
What Does Code U Mean?
The letter U on the Lennox EL296UHV seven-segment display indicates a discharge air temperature reading. The system is showing the current temperature of the air leaving the furnace. This is measured by a sensor in the supply air plenum or at the furnace outlet.
The discharge air temperature is useful for diagnosing performance issues. During heating, typical discharge temperatures range from 120 to 150 degrees Fahrenheit, depending on the heating stage and airflow settings. During cooling, discharge temperatures are typically 15 to 25 degrees below the return air temperature.
This is a diagnostic readout, not an error code. No action is required. HVAC technicians use this reading to verify that the system is producing the expected temperature rise across the heat exchanger or temperature drop across the evaporator coil.
When to Call a Professional
Contact a licensed HVAC technician if:
- The discharge temperature seems unusually low during heating (below 100F)
- The discharge temperature seems unusually high during heating (above 170F)
✓ Verified against manufacturer service manual — March 2026