McQuay WMC Fault Code E05
McQuay WMC Fault Code E05 is a warning alarm indicating: Evaporator water flow fault. The most common causes include Chilled water pump stopped or failed. Estimated repair time: 1-2 hours. This alarm requires immediate attention by a certified HVAC technician.
Alarm Description
Evaporator water flow fault
Brand: McQuay | Model: WMC (Water-Cooled Screw Chiller) | Code: E05 | Severity: Warning
Observable Symptoms
- Water flow indicator shows zero or low flow
- Differential pressure across evaporator or condenser is low
- Pump may not be running or making abnormal noise
What to Check First
Before diving into detailed diagnostics, start with this quick first check:
Probable Causes
- Chilled water pump stopped or failed
- Flow switch stuck or misaligned
- Strainer clogged in water line
- Air trapped in chilled water loop
Recommended Inspection Steps
- Verify chilled water pump is operating
- Check flow switch operation and setting
- Clean Y-strainer or basket filter
- Bleed air from system at high points
- Replace flow switch if faulty
Required Tools & Equipment
- Coil cleaning brush and coil cleaner
- 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 E05 mean?
Fault code E05 on a McQuay WMC chiller indicates: Evaporator water flow fault. This is a warning alarm that requires diagnostic attention.
What causes McQuay WMC alarm code E05?
Common causes include: Chilled water pump stopped or failed; Flow switch stuck or misaligned; Strainer clogged in water line
How do I fix McQuay WMC error code E05?
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.