York YK Fault Code E4

E4
VSD over-temperature
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

York YK Fault Code E4 is a warning alarm indicating: VSD over-temperature. The most common causes include VSD heatsink temperature high. Estimated repair time: 45-90 minutes. This alarm requires immediate attention by a certified HVAC technician.

Alarm Description

VSD over-temperature

Brand: York  |  Model: YK (Centrifugal Chiller (Water-Cooled))  |  Code: E4  |  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:

Quick Start: Check VSD temperature

Probable Causes

  • VSD heatsink temperature high
  • Cooling fan failure
  • Ambient too high

Recommended Inspection Steps

  1. Check VSD temperature
  2. Verify cooling fan
  3. Improve ventilation

Required Tools & Equipment

  • Infrared thermometer or calibrated temperature probe
  • 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 York service representative for warranty-covered repairs

Related Fault Codes

Other York YK codes that may be related:

E1E2E3E5E6

OEM Service Manual Reference

OEM Reference: York YK Centrifugal Chiller Service Manual (Form 160.60-S1). Johnson Controls Technical Literature.

Frequently Asked Questions

What does York YK fault code E4 mean?

Fault code E4 on a York YK chiller indicates: VSD over-temperature. This is a warning alarm that requires diagnostic attention.

What causes York YK alarm code E4?

Common causes include: VSD heatsink temperature high; Cooling fan failure; Ambient too high

How do I fix York YK error code E4?

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 York 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 York YK service procedures.