Fault Code Lookup

HVAC Sales Master
E227
Low pressure switch open during trial for ignition or run mode
This code typically points to
  • Intermittent venting
  • Marginal switch hold-in

Next checks to confirm
  1. Measure switch closing pressure
  2. Measure operating pressure
  3. Inspect vent and inducer

Escalation
Heat sequence abort / recycle
Reset behavior
Resumes normal operation after fault clears.
Urgent
Fix now
Source
Lennox unit information doc 100027, p.13