McQuay WMC Fault Code E21
McQuay WMC Fault Code E21 is a warning alarm indicating: High bearing temperature. The most common causes include Bearing lubrication inadequate. Estimated repair time: 1-2 hours. This alarm requires immediate attention by a certified HVAC technician.
Alarm Description
High bearing temperature
Brand: McQuay | Model: WMC (Water-Cooled Screw Chiller) | Code: E21 | 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
- Bearing lubrication inadequate
- Bearing wear
- Cooling oil flow insufficient
- Excessive vibration
Recommended Inspection Steps
- Check bearing temperature sensors
- Verify oil circulation to bearings
- Measure vibration
- Inspect bearings if accessible
Required Tools & Equipment
- Infrared thermometer or calibrated temperature probe
- Oil level sight glass inspection tool
- 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 McQuay service representative for warranty-covered repairs
Related Fault Codes
Other McQuay WMC codes that may be related:
OEM Service Manual Reference
OEM Reference: McQuay WMC Water-Cooled Screw Chiller Service Manual. Available through Daikin Applied (formerly McQuay) technical support.
Frequently Asked Questions
What does McQuay WMC fault code E21 mean?
Fault code E21 on a McQuay WMC chiller indicates: High bearing temperature. This is a warning alarm that requires diagnostic attention.
What causes McQuay WMC alarm code E21?
Common causes include: Bearing lubrication inadequate; Bearing wear; Cooling oil flow insufficient
How do I fix McQuay WMC error code E21?
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 McQuay service representative.