Fault Code Lookup

HVAC Sales Master
E163
Refrigerant leak detector control failure
This code typically points to
  • Refrigerant detection control failure / board-level low-GWP control problem

Next checks to confirm
  1. Verify low-GWP control functionality
  2. Replace the failed low-GWP control / board if the fault persists

Escalation
Low-GWP control fault
Reset behavior
Clears when the control fault is corrected.
Safety Critical
Immediate concern
Cross-generation conflict
Codes E150, E151, E152, E154, E155, E160, E161, E163, E164, and E390 only exist on K-revision Lennox furnaces (EL195UHNEK, ML196UHEK). These are refrigerant leak detection codes for R-454B A2L compliance. E154/E155 will latch the blower ON for at least 5 minutes regardless of thermostat call — this is a code-mandated safety behavior. A2L refrigerant detection CANNOT be disabled — it's prohibited by safety codes.
Source
Lennox EL195UHNEK Installation Instructions 508575-01, p.46