Lennox TCS Fault Code E25
Lennox TCS Fault Code E25 is a warning alarm indicating: Pumpdown sequence fault. The most common causes include Pumpdown solenoid not closing. Estimated repair time: 1-2 hours. This alarm requires immediate attention by a certified HVAC technician.
Alarm Description
Pumpdown sequence fault
Brand: Lennox | Model: TCS (Water-Cooled Screw 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
- Pumpdown solenoid not closing
- System pressure not reaching pumpdown setpoint
- Timer expired
Recommended Inspection Steps
- Check pumpdown solenoid
- Verify system pressure
- Inspect pumpdown logic
- Manual pumpdown if needed
Required Tools & Equipment
- Digital multimeter
- OEM service manual
- Safety PPE (gloves, safety glasses)
- 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 TCS codes that may be related:
OEM Service Manual Reference
OEM Reference: Lennox TCS Water-Cooled Screw Chiller Service Manual. Available through Lennox Commercial technical support.
Frequently Asked Questions
What does Lennox TCS fault code E25 mean?
Fault code E25 on a Lennox TCS chiller indicates: Pumpdown sequence fault. This is a warning alarm that requires diagnostic attention.
What causes Lennox TCS alarm code E25?
Common causes include: Pumpdown solenoid not closing; System pressure not reaching pumpdown setpoint; Timer expired
How do I fix Lennox TCS 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.