Lennox LCA Fault Code E25
Lennox LCA Fault Code E25 is a warning alarm indicating: Evaporator approach temperature high. The most common causes include Fouled tubes. Estimated repair time: 4-6 hours (requires isolating water circuit, mechanical or chemical tube cleaning). This alarm requires immediate attention by a certified HVAC technician.
Alarm Description
Evaporator approach temperature high
Brand: Lennox | Model: LCA (Air-Cooled Chiller) | Code: E25 | 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
- Fouled tubes
- Low charge
- Distribution issue
- Flow low
Recommended Inspection Steps
- Calculate approach
- Inspect tubes
- Verify charge
- Measure flow
- Clean tubes
Required Tools & Equipment
- Coil cleaning brush and coil cleaner
- Infrared thermometer or calibrated temperature probe
- PT chart for refrigerant type
- Safety PPE (gloves, safety glasses, face shield)
Estimated Repair Time
4-6 hours (requires isolating water circuit, mechanical or chemical tube cleaning)
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:
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 E25 mean?
Fault code E25 on a Lennox LCA chiller indicates: Evaporator approach temperature high. This is a warning alarm that requires diagnostic attention.
What causes Lennox LCA alarm code E25?
Common causes include: Fouled tubes; Low charge; Distribution issue
How do I fix Lennox LCA error code E25?
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.