Lennox SCA Fault Code E28
Lennox SCA Fault Code E28 is a warning alarm indicating: Surge protection activated. The most common causes include Voltage surge detected by surge protection device. Estimated repair time: 1-2 hours. This alarm requires immediate attention by a certified HVAC technician.
Alarm Description
Surge protection activated
Brand: Lennox | Model: SCA (Air-Cooled Scroll Chiller) | Code: E28 | 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
- Voltage surge detected by surge protection device
- Lightning strike nearby
- Utility power transient
Recommended Inspection Steps
- Check surge protection device status
- Verify no damage to electrical components
- Reset surge protection device
- Inspect all electronic controls for damage
Required Tools & Equipment
- Digital multimeter
- 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 SCA codes that may be related:
OEM Service Manual Reference
OEM Reference: Lennox SCA Air-Cooled Scroll Chiller Service Manual. Available through Lennox Commercial technical support.
Frequently Asked Questions
What does Lennox SCA fault code E28 mean?
Fault code E28 on a Lennox SCA chiller indicates: Surge protection activated. This is a warning alarm that requires diagnostic attention.
What causes Lennox SCA alarm code E28?
Common causes include: Voltage surge detected by surge protection device; Lightning strike nearby; Utility power transient
How do I fix Lennox SCA error code E28?
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.