| Fan motor will not run. | No power | Check voltage at electrical outlet. Correct if none. |
| Power supply cord | Check voltage at the power cord terminal. Replace the power cord if none. |
| Wire disconnected or connection loose | Connect wire. Refer to wiring diagram for terminal identification. Repair or replace loose terminal. |
| Main switch failure | Check and replace the main switch if failure. |
| Capacitor (Discharge capacitor before testing) | Test capacitor. Replace if not within +/-10% of manufacture's rating. Replace if shorted, open or damaged. |
| Will not rotate | Fan blade hitting shroud or blower hitting scroll. Realign assembly. Check fan motor bearings. Replace the motor if motor shaft do not rotate. |
| Fan motor runs intermittently | Cycles on overload. | Check voltage. Call an electrician if not within limits. |
| Test capacitor. Replace if not within +/-10% of manufacture's rating. |
| Check bearings. Replace the motor if the fan blade cannot rotate freely. |
| Pay attention to any change from high speed to low speed. Replace the motor if the speed does not change. |
| Fan motor noise. | Fan | Replace the fan if cracked, out of balance, or partially missing. |
| Blower | Replace the blower if cracked, out of balance, or partially missing. |
| Loose screws | Tighten them. |
| Worn bearings | Replace the motor if knocking sounds continue when running or loose, or the motor hums or noise appears to be internal while running. |
| The compressor not to stop even the room temperature has got to the setting temperature. | Thermostat | Check and replace if the thermostat is damaged. |
| Insufficient cooling. | Air filter | Clean or replace if restricted. |
| Vent, door | Close if open. |
| Unit undersized | Determine if the unit is properly sized for the area to be cooled or heated. |
| Condenser and Evaporator | Clean or replace if restricted. |
| Fan motor | Check the fan capacitor and replace if not within +/-10% of manufactures rating. |
| Room structure | Take proper measures to make the door and windows sealed well if gap is found. |
| Air flow | Clean or remove if any barrier is found to block the inlet/outlet wind flow of the unit. |
| Sunlight | Add a awning if the condenser is exposed to the sunlight. |
| Less refrigerant | Check the tubes for reasons of leakage. Recycle the refrigerant, correct the leakage points and recharge. |
| Capillary tube | Regulate the flow if capillary tube and make the evaporating temperature appropriate if the evaporator is frosted. Replace if blocked. Repair joint if leaking. |
| Compressor | The inlet and outlet valve of the compressor is damaged, making the low pressure connected with the high pressure. The refrigerating system can not produce high pressure and low pressure. Replace the compressor after checking for the reason. |
| reverse valve | The seal in valve is damaged, making the low pressure connected with the high pressure. The refrigerating system can not produce high pressure and low pressure. Replace the reverse valve after checking for the reason. |
| Drainage | The drainage is blocked. It will increase the efficiency in cooling mode, but will cause the condenser to frost in heating mode. |
| Stop instantly after startup. | Refrigerant | The amount of the refrigerant is too much, making the compressor load too big. Recycle and recharge the refrigerant after checking for the reason. |
| Compressor | The compressor is seized. Replace after checking for the reason. |
| No cooling or heating. | No power | Check the voltage. Call an electrician if no within the limit. |
| Wiring | Check the terminals. Repair and correct if loose. |
| Temperature setting | Check and adjust the thermostat. |
| Main switch setting | Check and adjust the main switch setting. |
| Reverse valve wire | Check the resistance of reverse valve wire. Replace the wire if short, open or damaged. |
| Reverse valve | If the reverse valve is blocked, the heating mode will not perform. Replace the reverse valve after checking the reason. |
| Compressor will not run while fan motor runs. | Voltage | Check voltage. Call Supply Authority if not within limits. |
| Wiring | Check the wire connections, if loose, repair or replace the terminal. If wires are off, refer to wiring diagram for identification, and replace. Check wire locations. If not per wiring diagram, correct. |
| Main switch failure | Check and replace the main switch if failure. |
| Capacitor (Discharge capacitor before testing) | Check the capacitor. Replace if not within +/-10% of manufacturers rating. Replace if shorted, open, or damaged. |
| Thermostat | Check the thermostat setting if not at the coolest (in cooling mode) or the warmest (in heating mode). Set it if not. |
| Compressor | Check the compressor for open circuit or ground. If open or grounded, replace the compressor. |
| Excessive noise. | Copper tubing | Remove the cabinet and carefully rearrange tubing not to contact cabinet, compressor, shroud and barrier. |
| The unit starts and stops frequently. | Power supply | The input power supply voltage is too low. Call an electrician if not within limits. |
| Outdoor temperature | When the outdoor temperature is too high, the compressor will protect. |