Daikin Applied Americas formerly known as McQuay International is a company that designs, manufactures, and sells ventilation, heating, and air conditioners for commercial buildings. The company offers a wide range of products, systems, services, and parts that are ideal for your business needs. Purchased in Daikin Industries in 2006, McQuay became a subsidiary with headquarters in Minneapolis, Minnesota, USA.
While being a subsidiary the company offers products all over the world with the help of distributors and sales representatives. Focusing on its aim the company only offers the products it started with, but now its range includes systems that are suitable for home and commercial use.
McQuay might be a high-ranking company, but from time to time customers have complained about system errors. Fortunately, most of these errors can be fixed on your own. So rather than ignoring the error codes, your appliance is showing its time to note down the McQuay air conditioner error code and get to the bottom of the problem. To help you out we have listed down the most common error codes of McQuay air conditioners.
Codes List
| Error Codes | Problem |
|---|---|
| E1 | Compressor 2 low pressure faulty |
| E2 | Compressor 2 high pressure faulty |
| E3 | Compressor 2 overload |
| E4 | Indoor coil 2 temperature sensor fault |
| E5 | System 2 leaving water temperature 2 faulty |
| F2 | Indoor coil 1 temperature sensor fault |
| F4 | Return air temperature sensor fault |
| F6 | Communication faulty |
| F9 | Compressor 1 refrigerant leak |
| FE | Compressor 2 refrigerant leak |
| H1 | Compressor 1 overload |
| H4 | Compressor 1 high pressure faulty |
| L1 | Compressor 1 low pressure faulty |
| L3 | Temperature of water entering too high or low |
| L4 | Water flow switch faulty |
| L5 | System 1 leaving water temperature 1 faulty |
Remote Control
Y Model Indoor Series Codes
| Error Codes | Error Description |
|---|---|
| 0 | Normal |
| F6 | Heat exchanger overheat |
| U0 | Insufficient gas |
| H0 | Compressor sensor system abnormality |
| U2 | DC voltage out of range |
| H3 | High pressure switch error |
| U4 | Communication error |
| H6 | Position sensor abnormality |
| U7 | Signal transmission error (on outdoor unit PCB) |
| H8 | AC current sensor error |
| UA | Installation error |
| H9 | Outdoor air thermistor short / open |
| UF | Communication Error (indoor and outdoor) piping and wiring |
| J1 | Pressure sensor error |
| UH | Anti-freeze function in other room |
| J3 | Compressor discharge pipe thermistor short /open / misplaced |
| A1 | Indoor PCB error |
| J5 | Suction pipe thermistor short/ open |
| A3 | Water pump error |
| J6 | Outdoor heat exchanger |
| A5 | Antifreeze |
| J7 | Subcooling heat exchanger thermistor short/ open |
| A6 | Indoor fan motor abnormal |
| J8 | Liquid pipe thermistor short/ open |
| C4 | Indoor heat exchanger thermistor short/ open |
| J9 | Gas pipe thermistor abnormality |
| C9 | Indoor room thermistor short/ open |
| LC | Communication error (control PCB and inverter PCB) |
| L1 | Outdoor PCB error |
| L3 | Electrical box temperature rise |
| L4 | Heat sink overheat |
| E1 | Outdoor PCB error |
| E3 | High pressure protection |
| E4 | Low pressure protection |
| E5 | Compressor motor lock |
| L5 | IPM error / IGBT error |
| E6 | Compressor start-up error |
| L8 | Electrical thermal switch |
| E7 | Outdoor DC fan motor lock |
| L9 | Stall prevention |
| E8 | Ac input over current |
| P1 | Open phase or voltage unbalance |
| E9 | EXV error |
| P4 | Heat sink thermistor short / open |
| EA | 4-way valve error |
| PJ | Capacity setting error |
| F3 | Discharge pipe overheat |
Wall Mounted K-Series Codes
| Error Codes | Meaning |
|---|---|
| 00 | Normal |
| UA | Indoor-outdoor Unit Combination Fault |
| UO | Refrigerant Shortage |
| U2 | Drop Voltage Or Main Circuit Overvoltage |
| U4 | Failure Of Transmission (Between Indoor Unit And Outdoor Unit) |
| A1 | Indoor Pcb Defectiveness |
| A5 | High Pressure Control Or Freeze-up Protector |
| A6 | Fan Motor Fault |
| C4 | Faulty Heat Exchanger Temperature Sensor |
| C9 | Faulty Suction Air Temperature Sensor |
| EA | Cooling-heating Switching Error |
| E1 | Circuit Board Fault |
| E5 | Ol Started |
| E6 | Faulty Compressor Start Up |
| E7 | Dc Fan Motor Fault |
| E8 | Overcurrent Input |
| F3 | High Temperature Discharge Ppe Control |
| F6 | High Pressrue Control (In Cooling) |
| H0 | Sensor Fault |
| H6 | Operation Fault Due To Faulty Position Detection Sensor |
| H8 | Dc Current Sensor Fault |
| H9 | Faulty Suction Air Temperature Sensor |
| J3 | Faulty Discharge Pipe Temperature Sensor |
| J6 | Faulty Heat Exchanger Temperature Sensor |
| L3 | Electrical Parts Heat Fault |
| L4 | High Temperature At Inverter Circuit Heatsink |
| L5 | Output Overcurrent |
| P4 | Faulty Inverter Circuit Heatsink Temperature Sensor |
Error Diagnosis by Wired Controller (MC301)
| Error Messages | Meaning |
|---|---|
| E0 | System malfunction |
| E1 | Sensor Broken (TH1 discharge Temp.) |
| E2 | Sensor Broken (TH2 inlet coil 1#) |
| E3 | Sensor Broken (TH3 mid coil 1#) |
| E4 | Sensor Broken (TH4 inlet coil 2#) |
| E5 | Sensor Broken (TH5 mid coil 2#) |
| E6 | Sensor Broken (TH6 inlet coil 3#) |
| E7 | Sensor Broken (TH7 mid coil 3#) |
| E8 | Sensor Broken (TH8 ambient temp) |
| E9 | Sensor Broken (TH9 outlet coil) |
| EA | Sensor Broken (TH10 subcool outlet) |
| EB | Sensor Broken (TH11 subcool suction) |
| EC | Sensor Broken (TH12 suction) |
| EF | Emergency Run |
| F0 | Outdoor Storage Malfunction |
| F1 | Sensor Broken (indoor inlet coil) |
| F2 | Sensor Broken (indoor mid coil) |
| F3 | Sensor Broken (indoor outlet coil) |
| F4 | Sensor Broken (indoor return air) |
| F5 | Sensor Broken (indoor supply air) |
| F6 | Indoor and controller communication malfunction |
| F7 | Ambient temp exceed the limit |
| F8 | 4WV malfunction |
| F9 | Refrigerant leakage |
| FA | Controller storage malfunction |
| FB | Water Pump (indoor water pump) |
| FC | Indoor and outdoor communication malfunction |
| FE | Outdoor master and slave communication malfunction |
| H0 | Digital comp overload |
| H1 | Fixed Comp1 overload |
| H2 | Fixed Comp2 overload |
| H3 | Fixed Comp3 overload |
| H4 | High pressure too high |
| H5 | Sensor broken, high pressure |
| H6 | Discharge temp too high |
| L0 | Super heat too low |
| L1 | Low pressure too low |
| L2 | Sensor broken, low pressure |
| 10 | System malfunction |
| 11 | Sensor broken (slave TH1 discharge temp) |
| 12 | Sensor broken (slave TH2 inlet coil 1#) |
| 13 | Sensor Broken (slave TH3 mid coil 1#) |
| 14 | Sensor broken (slave TH4 inlet coil 2#) |
| 15 | Sensor broken (slave TH5 mid coil 2#) |
| 16 | Sensor broken (slave TH6 inlet coil 3#) |
| 17 | Sensor broken (slave TH7 mid coil 3#) |
| 18 | Sensor broken (slave TH8 ambient temp) |
| 19 | Sensor broken (slave TH9 outlet coil) |
| 1A | Sensor broken (slave TH10 subcool outlet) |
| 1B | Sensor broken (slave TH11 subcool suction) |
| 1C | Sensor Broken (slave TH12 suction) |
| 1F | Emergency run (slave) |
| 20 | Outdoor storage (slave) |
| 27 | Ambient temp exceed the limit (slave) |
| 28 | 4WV malfunction (slave) |
| 29 | Refrigerant leakage (slave) |
| 30 | Digital comp overload (slave) |
| 31 | Fixed comp1 overload (slave) |
| 32 | Fixed comp2 overload (slave) |
| 33 | Fixed comp 3 overload (slave) |
| 34 | High pressure too high (slave) |
| 35 | Sensor broken, high pressure (slave) |
| 36 | Discharge temp too high (slave) |
| 40 | Super heat too low (slave) |
| 41 | Low pressure too low (slave) |
| 42 | Sensor broken, low pressure (slave) |
Cassette AC Codes
Wired Remote Control (Universal Board)
Display: E1 Blinking
Faulty Indication: Room sensor contact loose/ short
Display: E2 Blinking
Faulty Indication: Indoor coil sensor contact loose/ short
Display: E3 Blinking
Faulty Indication: Outdoor coil sensor contact loose/ short
Display: E4 Blinking
Faulty Indication: Compressor overload
Display: E5 Blinking
Faulty Indication: Gas leak
Display: E6 Blinking
Faulty Indication: Pump faulty
Display: Heat LED Blinking
Faulty Indication: Outdoor defrost (for Heatpump only)
PTAC Codes
Remote Controller Error Display:
E01: Room temperature sensor open. Automatically reset to restoration error.
E02: Room temperature sensor short. Automatically reset to restoration error.
E03: Error input from indoor unit or Outdoor unit.
Rooftop Package
When the system is on and an error occurs, the ON/OFF LED on the LCD panel will blink and an error code is shown. When the system is off and there is a thermistor error, the ON/OFF LED is off but the error code is still displayed. Each error code represents different message as below.
| Error Codes | Possible Fault |
|---|---|
| E01 | Require manual reset (possible causes) |
| E02 | Compressor 1 high temperature (overload) |
| E03 | Compressor 2 high temperature(overload) |
| E06 | Compressor 1 high pressure trip / contact open |
| E07 | Compressor 2 high pressure trip / contact open |
| E10 | Compressor 1 trip / low R-22 / outdoor abnormal |
| E11 | Compressor 2 trip / low R-22 / outdoor abnormal |
| E14 | Room sensor short |
| E15 | Room sensor open |
| E16 | Indoor coil sensor 1 short |
| E17 | Indoor coil sensor 2 short |
| E20 | Indoor coil sensor 1 open |
| E21 | Indoor coil sensor 2 open |
| E24 | Outdoor coil sensor 1 short |
| E25 | Outdoor coil sensor 2 short |
| E28 | Outdoor coil sensor 1 open |
| E29 | Outdoor coil sensor 2 open |
| E32 | Compressor 1 de-ice |
| E33 | Compressor 2 de-ice |
Troubleshooting
When a malfunction of the air conditioner unit is detected, immediately switch off the main power supply before proceeding with the following troubleshooting procedures.
The following are common fault conditions and simple troubleshooting tips. If any other fault conditions which are not listed occur, contact your nearest local dealer. DO NOT attempt to troubleshoot the unit by yourself.
| Fault Condition | Possible Cause |
|---|---|
| The air conditioner unit will not resume after power failure. | The auto restart function is not functioning. Please turn on the unit with the wireless / wired controller. |
| The airfl ow is too slow or room cannot be cooled suffi ciently. | |
| Discharge airfl ow has bad odor. | |
| Condensation on the front air grille of the indoor unit. | |
| Water fl owing out from the air conditioner. | Switch off the unit and contact your nearest dealer. This might be due to tilted installation. |
| Hissing airfl ow sound from the air conditioner unit during operation. | Liquid refrigerant fl owing into the evaporator coil. |
| The wireless controller display is dim. | |
| Compressor operates continuously. | |
| No cool air comes out during cooling cycle, or no hot air comes out during heating cycle. | |
| On heating cycle, warm air does not come out. | Unit is in defrost mode. Heating operation will resume after defrost cycle ends. |
LED Indicator Lights
Normal Operation and Fault Conditions for Heat Pump Unit
Manuals Pdf
McQuay Air Conditioning Manual PDF
McQuay Rooftop Packaged AC Manual PDF
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*If you can't find the code you're looking for on our site, please let us know, and we'll update our database as soon as possible.
E9 cassette?
What is code “PH”? I have a McQuay MQIS-164024-CWF216A which is giving me this code. Can you help? Thanks.