McQuay WMC Fault Code E31
McQuay WMC Fault Code E31 is a warning alarm indicating: Refrigerant level alarm. The most common causes include Refrigerant level sensor indicating low charge. Estimated repair time: 1-2 hours. This alarm requires immediate attention by a certified HVAC technician.
Alarm Description
Refrigerant level alarm
Brand: McQuay | Model: WMC (Water-Cooled Screw Chiller) | Code: E31 | 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
- Refrigerant level sensor indicating low charge
- Refrigerant leak in system
- Subcooling below expected value
Recommended Inspection Steps
- Check refrigerant level sensor reading
- Verify subcooling value
- Perform leak test
- Repair leak and recharge to proper amount
Required Tools & Equipment
- EPA-certified refrigerant recovery unit
- Electronic leak detector
- PT chart for refrigerant type
- 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 E31 mean?
Fault code E31 on a McQuay WMC chiller indicates: Refrigerant level alarm. This is a warning alarm that requires diagnostic attention.
What causes McQuay WMC alarm code E31?
Common causes include: Refrigerant level sensor indicating low charge; Refrigerant leak in system; Subcooling below expected value
How do I fix McQuay WMC error code E31?
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.