Error Code d
Info

Lennox EL296UHV Error Code d: Dehumidification Mode

TL;DR
Your Lennox EL296UHV is running in dehumidification mode. This is a normal operating state controlled by your iComfort thermostat.
Disclaimer
This article is for informational purposes only and does not guarantee the accuracy or completeness of the information provided. Always turn off power and gas supply before attempting any repairs. If you smell gas, leave immediately and call your gas company. Consult a licensed HVAC technician for diagnosis and repair. Any actions taken based on this information are at your own risk.

What Does Code d Mean?

A lowercase d on the Lennox EL296UHV seven-segment display indicates that the system is operating in dehumidification mode. The display blinks at 1 second on, 1 second off, followed by the current CFM setting. This mode is activated by the iComfort thermostat when indoor humidity levels exceed the set target.

During dehumidification, the system runs the air conditioning at reduced blower speed to maximize moisture removal from the air. The slower airflow allows the evaporator coil to get colder, which condenses more moisture from the passing air. This is a comfort feature rather than a fault condition.

No action is needed. The system will return to normal operation once the humidity level drops to the thermostat's target setting. If you want to adjust dehumidification behavior, change the humidity settings on your iComfort thermostat.

When to Call a Professional

Contact a licensed HVAC technician if:

Sources

  1. Lennox EL296UHV Unit Information (Corp. 1125-L5)

✓ Verified against manufacturer service manual — March 2026