OEM Service Manual: McQuay WMC Water-Cooled Screw Chiller Service Manual. Available through Daikin Applied (formerly McQuay) technical support.
32 codes
| Fault Code | Alarm Description | Severity | Probable Causes | Action |
|---|---|---|---|---|
| E01 | Compressor high pressure protection | Critical | Condenser water flow insufficient | View Details → |
| E02 | Compressor low pressure protection | Warning | Low refrigerant charge | View Details → |
| E03 | Compressor motor overload | Critical | Compressor motor bearing failure | View Details → |
| E04 | Compressor discharge temperature high | Warning | Compression ratio too high from high head pressure | View Details → |
| E05 | Evaporator water flow fault | Warning | Chilled water pump stopped or failed | View Details → |
| E06 | Condenser water flow fault | Warning | Condenser water pump stopped | View Details → |
| E07 | Evaporator water temperature low | Warning | Chilled water setpoint set too low | View Details → |
| E08 | Temperature sensor fault | Warning | Sensor element failure or drift | View Details → |
| E09 | Communication fault | Warning | Network cable damaged or disconnected | View Details → |
| E10 | Phase loss or reversal protection | Critical | One phase of power supply missing | View Details → |
| E11 | Overcurrent protection | Critical | Compressor motor overload | View Details → |
| E12 | Oil pressure low | Critical | Oil pump failure or internal wear | View Details → |
| E13 | Oil level low | Critical | Refrigerant leak carrying oil from system | View Details → |
| E14 | Expansion valve fault | Warning | Electronic expansion valve stepper motor failure | View Details → |
| E15 | Power supply fault | Warning | Voltage outside acceptable range | View Details → |
| E16 | Condenser fan fault | Warning | Condenser fan motor failure | View Details → |
| E17 | Condenser fan 2 fault | Warning | Condenser fan 2 motor failure | View Details → |
| E18 | Compressor vibration alarm | Warning | Compressor mounting bolts loose | View Details → |
| E19 | Pumpdown failure | Warning | Pumpdown solenoid valve not closing | View Details → |
| E20 | Compressor surge alarm | Warning | Operating conditions near surge line | View Details → |
| E21 | High bearing temperature | Warning | Bearing lubrication inadequate | View Details → |
| E22 | Low subcooling alarm | Warning | Refrigerant charge low | View Details → |
| E23 | High superheat alarm | Warning | Expansion valve starving | View Details → |
| E24 | Low oil differential pressure | Critical | Oil pump wear | View Details → |
| E25 | Compressor start inhibit | Warning | Safety interlock preventing compressor start | View Details → |
| E26 | Evaporator approach temperature high | Warning | Fouled evaporator tubes | View Details → |
| E27 | Condenser approach temperature high | Warning | Fouled condenser tubes | View Details → |
| E28 | Chiller staging error | Warning | Compressor staging logic error | View Details → |
| E29 | Energy efficiency alarm | Warning | Chiller operating below expected efficiency | View Details → |
| E30 | Compressor runtime exceeded | Warning | Compressor has exceeded maximum continuous runtime | View Details → |
| E31 | Refrigerant level alarm | Warning | Refrigerant level sensor indicating low charge | View Details → |
| E32 | Cooling tower water fault | Warning | Cooling tower fan not operating | View Details → |
Disclaimer: All McQuay WMC fault code 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.