Lennox SCA Fault Code E27
Lennox SCA Fault Code E27 is a warning alarm indicating: Water flow proving 2. The most common causes include Water flow proving switch on circuit 2 not closing. Estimated repair time: 45-90 minutes. This alarm requires immediate attention by a certified HVAC technician.
Alarm Description
Water flow proving 2
Brand: Lennox | Model: SCA (Air-Cooled Scroll Chiller) | Code: E27 | Severity: Warning
Observable Symptoms
- Water flow indicator shows zero or low flow
- Differential pressure across evaporator or condenser is low
- Pump may not be running or making abnormal noise
What to Check First
Before diving into detailed diagnostics, start with this quick first check:
Probable Causes
- Water flow proving switch on circuit 2 not closing
- Flow rate on circuit 2 insufficient
- Flow switch 2 faulty
Recommended Inspection Steps
- Verify water flow on circuit 2
- Check flow proving switch 2
- Adjust or replace flow switch 2
Required Tools & Equipment
- Digital multimeter
- OEM service manual
- Safety PPE (gloves, safety glasses)
- Safety PPE (gloves, safety glasses, face shield)
Estimated Repair Time
45-90 minutes
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 E27 mean?
Fault code E27 on a Lennox SCA chiller indicates: Water flow proving 2. This is a warning alarm that requires diagnostic attention.
What causes Lennox SCA alarm code E27?
Common causes include: Water flow proving switch on circuit 2 not closing; Flow rate on circuit 2 insufficient; Flow switch 2 faulty
How do I fix Lennox SCA error code E27?
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.