Lennox SCA Fault Code E17

E17
Low pressure safety 2
Warning
SAFETY WARNING: Commercial chillers contain high-pressure refrigerants and high-voltage electrical components (208V-4160V). Only EPA Section 608 certified technicians should perform diagnostic work. Always follow lockout/tagout procedures and wear appropriate PPE. Do not attempt repairs without proper training and equipment.
AI Summary

Lennox SCA Fault Code E17 is a warning alarm indicating: Low pressure safety 2. The most common causes include Low refrigerant charge on circuit 2. Estimated repair time: 45-90 minutes. This alarm requires immediate attention by a certified HVAC technician.

Alarm Description

Low pressure safety 2

Brand: Lennox  |  Model: SCA (Air-Cooled Scroll Chiller)  |  Code: E17  |  Severity: Warning

Observable Symptoms

  • Suction pressure gauge reads below normal operating range
  • Compressor may short cycle or run continuously without cooling
  • Frost may appear on suction line or evaporator

What to Check First

Before diving into detailed diagnostics, start with this quick first check:

Quick Start: Check charge on circuit 2

Probable Causes

  • Low refrigerant charge on circuit 2
  • Expansion valve 2 issue
  • Evaporator flow low on circuit 2

Recommended Inspection Steps

  1. Check charge on circuit 2
  2. Inspect expansion valve 2
  3. Measure water flow on circuit 2

Required Tools & Equipment

  • PT chart for refrigerant type
  • 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 E17 mean?

Fault code E17 on a Lennox SCA chiller indicates: Low pressure safety 2. This is a warning alarm that requires diagnostic attention.

What causes Lennox SCA alarm code E17?

Common causes include: Low refrigerant charge on circuit 2; Expansion valve 2 issue; Evaporator flow low on circuit 2

How do I fix Lennox SCA error code E17?

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.

Disclaimer: All lookup data is for reference only. Do not use this information to replace certified professional HVAC technician judgment. Always refer to original OEM official service manual for Lennox SCA service procedures.