Lennox EL296UHV Error Code E 226: High Pressure Switch Failed Closed
What Does Code E 226 Mean?
Error code E226 on the Lennox EL296UHV indicates that the high pressure switch has remained closed when the control board expected it to be open. Similar to E224 for the low pressure switch, this means the high pressure switch is stuck and not responding to actual draft conditions.
The high pressure switch should only close when the combustion air inducer is running at sufficient speed to create the higher draft level needed for high-fire operation. If the switch stays closed regardless of inducer status, it can no longer serve as a reliable safety device — the control board cannot trust it to accurately report venting conditions.
The most likely cause is a mechanically stuck switch diaphragm or contacts that have welded together. Condensation moisture entering the switch housing can also cause the contacts to stick. A technician needs to measure the operating pressure, verify the switch opens and closes at the correct pressure thresholds, and replace it if it is malfunctioning.
When to Call a Professional
Contact a licensed HVAC technician if:
- The pressure switch needs professional testing and likely replacement
- A technician should verify the operating pressure matches specifications
- The vent system should be inspected for condensation or drainage issues
✓ Verified against manufacturer service manual — March 2026