Fault Code Lookup

HVAC Sales Master
E225
High pressure switch failed open
This code typically points to
  • Pressure switch not making
  • Vent or inducer issue

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

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