Lennox LSB Fault Code E23
Lennox LSB Fault Code E23 is a warning alarm indicating: High superheat alarm. The most common causes include Valve starving. Estimated repair time: 1-2 hours. This alarm requires immediate attention by a certified HVAC technician.
Alarm Description
High superheat alarm
Brand: Lennox | Model: LSB (Water-Cooled Chiller) | Code: E23 | 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:
Probable Causes
- Valve starving
- Charge low
- Subcooling low
- Restriction
Recommended Inspection Steps
- Check superheat
- Inspect valve
- Verify subcooling
- Check restrictions
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 LSB codes that may be related:
OEM Service Manual Reference
OEM Reference: Lennox LSB Chiller Service Manual. Available through Lennox Commercial technical support.
Frequently Asked Questions
What does Lennox LSB fault code E23 mean?
Fault code E23 on a Lennox LSB chiller indicates: High superheat alarm. This is a warning alarm that requires diagnostic attention.
What causes Lennox LSB alarm code E23?
Common causes include: Valve starving; Charge low; Subcooling low
How do I fix Lennox LSB error code E23?
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.