Trane CVHF Fault Code 398

398
BAS Communication Lost
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

Trane CVHF Fault Code 398 is a warning alarm indicating: BAS Communication Lost. The most common causes include BAS cable fault. Estimated repair time: 30-90 minutes (requires network diagnostics and cable/connector inspection). This alarm requires immediate attention by a certified HVAC technician.

Alarm Description

BAS Communication Lost

Brand: Trane  |  Model: CVHF (Hermetic Centrifugal Chiller)  |  Code: 398  |  Severity: Warning

Observable Symptoms

  • Controller display shows communication error or blank screen
  • BAS/EMS system shows chiller as offline or in alarm state

What to Check First

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

Quick Start: Check cable

Probable Causes

  • BAS cable fault
  • BAS controller offline
  • Protocol mismatch

Recommended Inspection Steps

  1. Check cable
  2. Verify BAS controller
  3. Confirm protocol

Required Tools & Equipment

  • Safety PPE (gloves, safety glasses, face shield)
  • Wire tracing and continuity tester

Estimated Repair Time

30-90 minutes (requires network diagnostics and cable/connector inspection)

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 Trane service representative for warranty-covered repairs

Related Fault Codes

Other Trane CVHF codes that may be related:

EDFDF5B5BA

OEM Service Manual Reference

OEM Reference: Trane CVHF Hermetic Centrifugal Chiller Service Manual (SVR-SVN003-EN). Available through Trane Commercial support.

Frequently Asked Questions

What does Trane CVHF fault code 398 mean?

Fault code 398 on a Trane CVHF chiller indicates: BAS Communication Lost. This is a warning alarm that requires diagnostic attention.

What causes Trane CVHF alarm code 398?

Common causes include: BAS cable fault; BAS controller offline; Protocol mismatch

How do I fix Trane CVHF error code 398?

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 Trane 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 Trane CVHF service procedures.