Lennox LCA Fault Code E22

E22
Low subcooling alarm
Warning
SAFETY WARNING: Commercial chillers contain high-pressure refrigerants and high-voltage electrical components (208V-4160V). Only EPA Section 608 certified technicians should perform diagnostic work. Always follow lockout/tagout procedures and wear appropriate PPE. Do not attempt repairs without proper training and equipment.
AI Summary

Lennox LCA Fault Code E22 is a warning alarm indicating: Low subcooling alarm. The most common causes include Charge low. Estimated repair time: 1-2 hours. This alarm requires immediate attention by a certified HVAC technician.

Alarm Description

Low subcooling alarm

Brand: Lennox  |  Model: LCA (Air-Cooled Chiller)  |  Code: E22  |  Severity: Warning

Observable Symptoms

  • Controller displays alarm code and description
  • Chiller may be locked out or running in degraded mode
  • Alarm indicator light is illuminated on control panel

What to Check First

Before diving into detailed diagnostics, start with this quick first check:

Quick Start: Check subcooling

Probable Causes

  • Charge low
  • Condenser not subcooling
  • Valve overfeeding

Recommended Inspection Steps

  1. Check subcooling
  2. Verify charge
  3. Inspect valve
  4. Check receiver

Required Tools & Equipment

  • PT chart for refrigerant type
  • Safety PPE (gloves, safety glasses, face shield)

Estimated Repair Time

1-2 hours

When to Call a Professional

  • If the fault persists after completing all recommended inspection steps
  • If you observe unusual noises, vibrations, or oil leaks from the compressor
  • If refrigerant charge levels are outside OEM specifications and EPA-certified recovery is needed
  • If electrical measurements show voltage imbalance greater than 2% between phases
  • If the fault recurs immediately after reset, indicating an unresolved safety condition
  • Contact an authorized Lennox service representative for warranty-covered repairs

Related Fault Codes

Other Lennox LCA codes that may be related:

E01E02E03E04E05

OEM Service Manual Reference

OEM Reference: Lennox LCA Air-Cooled Chiller Service Manual. Available through Lennox Commercial technical support.

Frequently Asked Questions

What does Lennox LCA fault code E22 mean?

Fault code E22 on a Lennox LCA chiller indicates: Low subcooling alarm. This is a warning alarm that requires diagnostic attention.

What causes Lennox LCA alarm code E22?

Common causes include: Charge low; Condenser not subcooling; Valve overfeeding

How do I fix Lennox LCA error code E22?

Follow the recommended inspection steps below. Start with the quick check, then proceed through each step. If the fault persists after all steps, contact an authorized Lennox service representative.

Disclaimer: All lookup data is for reference only. Do not use this information to replace certified professional HVAC technician judgment. Always refer to original OEM official service manual for Lennox LCA service procedures.