Lennox EL296UHV Error Code E 223: Low Pressure Switch Failed Open
What Does Code E 223 Mean?
Error code E223 on the Lennox EL296UHV indicates that the low pressure switch failed to close during a call for heat. The pressure switch is a safety device that confirms the combustion air inducer is creating enough draft to safely vent exhaust gases before the burners are allowed to ignite.
When the inducer motor starts, it pulls air through the heat exchanger and out the exhaust vent, creating negative pressure. The low pressure switch senses this draft and closes its contacts. If the switch does not close, the SureLight control blocks ignition and displays this error code. The furnace resumes normal operation once the fault is cleared.
The most common cause is a blocked or restricted exhaust vent or combustion air intake. In winter, ice can form around the vent termination; bird nests, insect nests, leaves, and other debris can also block the vent at any time of year. Other causes include a failing inducer motor that cannot generate sufficient draft, a cracked or disconnected pressure switch hose, or a faulty pressure switch.
Common Causes
| Cause | Likelihood | DIY? |
|---|---|---|
| Blocked or restricted vent or combustion air intake | Most common | ✗ Call a pro → |
When to Call a Professional
Contact a licensed HVAC technician if:
- The vents appear clear but E223 persists
- The inducer motor sounds weak, rattles, or does not start
- The pressure switch hose is intact but the switch still will not close
- You see E271 (soft lockout from repeated pressure switch failures)
- The vent run is unusually long or has excessive elbows
Sources
- Unit Information - icomfort ENABLED EL296UHV(X) Series Units
✓ Verified against manufacturer service manual — March 2026