Slim Ducted Installation Manual
DURASTAR.COM
23
ISSUE POSSIBLE CAUSES
Both the indoor unit 
and outdoor unit make 
noises
Low hissing sound during operation: This is normal and is caused by 
refrigerant gas flowing through both indoor and outdoor units.
Low hissing sound when the system starts, has just stopped running, or 
is defrosting: This noise is normal and is caused by the refrigerant gas 
stopping or changing direction.
Squeaking sound: Normal expansion and contraction of plastic and 
metal parts caused by temperature changes during operation can cause 
squeaking noises.
The outdoor unit makes 
noises
The unit will make different sounds based on its current operating mode.
Dust is emitted from 
either the indoor or 
outdoor unit
The unit may accumulate dust during extended periods of non-use, 
which will be emitted when the unit is turned on. This can be mitigated by 
covering the unit during long periods of inactivity.
The unit emits a bad 
odor
The unit may absorb odors from the environment (such as furniture, 
cooking, cigarettes, etc.) which will be emitted during operations.
The unit’s filters have become moldy and should be cleaned.
The fan of the outdoor 
unit does not operate
During operation, the fan speed is controlled to optimize product 
operation.
Operation is erratic, 
unpredictable, or unit is 
unresponsive
Interference from cell phone towers and remote boosters may cause the 
unit to malfunction. In this case, try the following:
• Disconnect the power, then reconnect.
• Press ON/OFF button on remote control to restart operation.
NOTE
If problem persists, contact a local dealer or your nearest customer service center. Provide 
them with a detailed description of the unit malfunction as well as your model number.










