How to Read VRF Error Codes
VRF error codes display on the wired remote controller, the outdoor unit LED panel, or through the building management system. Each manufacturer uses a different code format. Daikin uses letter-number combinations (U4, E7). Mitsubishi uses similar notation (P6, E6). LG uses a CH prefix followed by a number.
The tables below cover the most common codes we see on Manhattan VRF service calls. This is not an exhaustive list. If your code is not listed, call us at 833-504-HVAC and we can advise over the phone.
Daikin VRV Error Codes
| Code | Meaning | Severity | Action |
|---|---|---|---|
| U4 | Communication error between outdoor and indoor units | High | Call for service. Can cascade across zones. |
| E7 | Compressor overcurrent / overload | High | Shut down system and call immediately. |
| L3 | High discharge pipe temperature | High | Possible refrigerant undercharge. Call for leak check. |
| L4 | Low pressure abnormality (inverter compressor) | High | Likely refrigerant leak. Call for service. |
| L5 | Low pressure abnormality (constant speed compressor) | High | Likely refrigerant leak. Call for service. |
| A3 | Drain level abnormality | Medium | Clogged condensate drain. Check drain pan and line. |
| A6 | Fan motor lock / abnormality | Medium | Fan motor may need replacement. |
| C4 | Heat exchanger thermistor short/open | Medium | Sensor replacement needed. |
| F3 | Discharge pipe temperature too high | High | Low charge or compressor issue. Call for service. |
| J3 | Discharge pipe thermistor malfunction | Medium | Sensor replacement needed. |
Mitsubishi City Multi Error Codes
| Code | Meaning | Severity | Action |
|---|---|---|---|
| P6 | Freeze/overheat protection (outdoor unit) | High | Communication or sensor fault. Call for service. |
| P9 | Outdoor unit communication error | High | M-NET bus issue. Call for service. |
| E6 | Compressor overcurrent | High | Shut down and call immediately. |
| E1 | Remote controller communication error | Medium | Check wiring. May need controller replacement. |
| L3 | Refrigerant charge abnormality | High | Likely leak. Call for leak detection. |
| U1 | High pressure switch tripped | High | Dirty condenser, overcharge, or airflow issue. |
| U3 | Short cycle / frequent starts | Medium | Check for control or refrigerant issues. |
| A1 | Indoor PCB abnormality | Medium | Board likely needs replacement. |
| F1 | Room temperature thermistor error | Low | Sensor replacement. Zone may not read temp correctly. |
| F6 | Heat exchanger overheating | High | Call for service. Check airflow and charge. |
LG Multi V Error Codes
| Code | Meaning | Severity | Action |
|---|---|---|---|
| CH 02 | Indoor unit abnormality | High | Communication failure. Call for service. |
| CH 05 | Communication error between indoor/outdoor | High | Wiring or board issue. Call for service. |
| CH 10 | Indoor unit fan motor abnormality | Medium | Fan motor may need replacement. |
| CH 21 | Compressor overcurrent | High | Shut down and call immediately. |
| CH 22 | Compressor current sensor error | High | Call for service. |
| CH 23 | DC link low voltage | High | Power supply or inverter issue. |
| CH 26 | Outdoor unit compressor overheating | High | Possible charge issue. Call for service. |
| CH 27 | Abnormal discharge pipe temperature | High | Low charge or compressor issue. |
When to Call a Technician
Any error code marked “High” severity should result in a service call. Do not attempt to clear high-severity codes by power cycling the system. This may temporarily clear the display but does not fix the underlying issue. In the case of compressor and refrigerant errors, running the system with an active fault can cause secondary damage.
Medium severity codes may allow continued operation with reduced performance, but should still be addressed within days rather than weeks. Low severity codes (typically sensor issues) should be scheduled for the next maintenance visit.
Got an Error Code?
Call Mountain Mechanical. We can often advise on severity over the phone and dispatch a factory-certified technician the same day.