Daikin Mini Split Troubleshooting
Daikin’s HVAC solutions, such as its mini-split units, are innovative, efficient and dependable. Although issues with these units are rare, this Daikin mini-split troubleshooting guide will help you identify and resolve problems quickly and easily.
These instructions are for mini-split room air conditioners, such as the FTXS18LVJU and CTXS07LVJU. Any testing or repairs outlined in this guide will need to be completed by an authorized technician.
Unit Won’t Turn On (Operation Lamp Is Off)
- No power to unit - Plug the power cord into an electrical outlet.
- Remote controller has no/dead batteries - Check the remote. If there are no batteries, put batteries in the remote; if the batteries are dead, replace them.
- Blown fuse or circuit breaker is off - Check the circuit breaker.
- Timer setting is incorrect - Set the timer correctly.
Unit Won’t Heat (Soon After The Start Of HEAT Operation)
- The air conditioner is warming up - Allow 1-4 minutes for the unit to warm up before it starts blowing hot air.
Air Conditioner Stopped Working Suddenly (Operation Lamp Is On)
- Sudden, large fluctuation in voltage - To protect the system, the unit may stop working in the event of a large, sudden change in voltage. The air conditioner should resume operation in about 3 minutes.
Air Conditioner Stopped Working Suddenly (Operation Lamp Is Flashing)
- Air filters are dirty - Clean the air filters.
- Air inlet/outlet of the indoor and/or outdoor units is blocked - If so, turn off the unit and remove the object(s) blocking the inlet/outlet. Then, turn the unit back on and try operating the air conditioner. If issues persist, service the unit.
- Indoor units are set to different modes - Make sure all the indoor units are set to the same mode and that the lamp is flashing.
Unit Doesn’t Cool / Heat Well
- Air filters are dirty - Clean the air filters.
- Air inlet/outlet of the indoor/outdoor units is blocked - Clear the obstruction so air can flow freely through the air inlet/outlet.
- Temperature setting is incorrect - Set the temperature appropriately: below the current room temperature for cooling, above the current temperature for warming.
- Windows and/or doors are open - Close the windows/doors to better control the indoor air temperature.
- Airflow rate and direction aren’t set properly - Set the airflow rate and direction properly.
Remote Controller Doesn’t Work Properly
- Batteries are dying - Low sensitivity, a display that’s low in contrast, no signals being displayed and the display running out of control often indicate dying batteries. When these issues occur, replace the batteries; if issues persist, service the unit.
HEAT Operation Can’t Be Selected (Unit Is A Heat Pump Model)
- DIP switch isn’t set properly - Flip the DIP switch to the left and then use the “MODE” button to select the HEAT operation.
The On/Off Timer Doesn’t Operate According To Settings
- On/Off timer and weekly timer aren’t set to the same time - Set the on/off and weekly timers to the same time or deactivate the weekly timer.
Indoor Unit Giving Off Odor
- Air conditioner has absorbed smells from the room - If the unit is discharging the smell of furniture, smoke or other odors, wash the machine to remove the odor.
Abnormal Functioning During Normal Operation
- Lightning or radio waves are causing the unit to behave oddly - If your unit starts acting strangely due to outside circumstances, turn the breaker off, turn it back on again and then try operating the air conditioner. If issues persist, service the unit.
Issues That Don’t Need Troubleshooting
The following issues don’t indicate problems with the unit. Although they may seem concerning, they’re part of normal operation:
The Louvers Don’t Start Moving Immediately After Startup
- The unit is adjusting the louver position - The louvers will start moving shortly.
Unit Stops Heating Suddenly And a Flowing Sound Is Heard
- The outdoor unit is defrosting - The HEAT operation should start in 4-12 minutes.
Unit Doesn’t Start Right Away
- The unit was turned on soon after it was turned off - The air conditioner will pause momentarily to protect the system and will begin operating normally in about 3 minutes.
- The current mode was reselected - The machine will pause for a moment to protect the system and will begin working normally in about 3 minutes.
Indoor Unit Is Making Noise
- Flowing - The refrigerant is flowing or water is being pumped.
- Blowing - The flow of refrigerant is switched over.
- Ticking - Air conditioner expands or contracts slightly due to temperature changes.
- Whistling - The refrigerant is flowing while the unit is defrosting.
- Clicking during operation or idle time - The refrigerant control valves or electrical parts operating.
Outdoor Unit Is Emitting Water or Steam
- The air conditioner is defrosting - The frost melts into water or steam as the unit defrosts.
- Moisture in the air is condensing - Condensation forms on the surface of the outdoor unit and piping when in COOL or DRY operation.
Mist Is Coming Out of the Indoor Unit
- Air in the room is cooled into mist by the cold airflow - This is normal during COOL operation.
- Air in the room is cooled into mist by the heat exchanger - This is normal while the unit is defrosting.
Outdoor Fan Rotates When the Air Conditioner Isn’t in Operation
- Fan continues rotating for 60 seconds - Once operation is stopped, it’s normal for the outdoor fan to continue rotating for 60 seconds. This is to protect the system and is part of normal operation.
- Outdoor air temperature is very high - If the temperature outside is very high, it’s normal for the outdoor fan to start rotating as a way of protecting the system.
Outdoor Unit Is Loud
- Frost on the heat exchanger - When frost forms on the outdoor unit’s heat exchanger, the operating sound increases slightly.
For more information about caring for your unit, see our Daikin mini-split cleaning article. If you need information on troubleshooting or caring for your specific unit, our large collection of Daikin manuals is a great resource.