HVAC Code Lookup

Lennox Furnace Code E227

Warning

The low pressure switch opened during the trial for ignition or while the furnace was running. Draft was lost partway through the heat cycle, so the control shut the burners down.

Manual wording: “Low pressure switch open during trial for ignition or run mode.”

Documented for: EL296UHE and SLP98UHV series

Likely causes, most common first

  1. Partially blocked intake or exhaust vent, including snow or ice at the termination
  2. Plugged condensate drain or trap
  3. Wet, cracked or loose pressure switch tubing
  4. Failing combustion air inducer

What you can safely check yourself

  • Check the outdoor intake and exhaust pipes for snow, ice, leaves or nesting debris
  • Check the condensate drain line and trap for a clog or standing water
  • Check that the furnace door is fully seated
  • Turn the furnace power switch off for 30 seconds and back on once

When to call a technician

If the vent and drain are clear and the code returns, the pressure switch, its tubing or the inducer needs testing with a manometer. Never jumper a pressure switch.

A Lennox furnace throwing this code repeatedly has a reason — clearing the code without fixing the cause just hides it.

Sources

Other Lennox codes