Concealed Ducted Air Handler Installation Manual
Troubleshooting
Page 10
Revised 5/14/2020
4
Troubleshooting
If any of the following conditions occurs, turn o your unit immediately!
• You smell a burning odor
• The unit emits loud or abnormal sounds
• A power fuse blows or the circuit breaker frequently trips
• Water or other objects fall into or out of the unit
DO NOT ATTEMPT TO FIX THESE YOURSELF! CONTACT AN AUTHORIZED SERVICE PROVIDER
IMMEDIATELY!
SAFETY PRECAUTIONS
Issue
Possible Causes
Unit does not turn
on when pressing
ON/OFF button
The Unit has a 3-minute protection feature that prevents the unit from overload-
ing. The unit cannot be restarted within three minutes of being turned o.
Cooling and Heating Models: If the Operation light and PRE-DEF (Pre-heating/
Defrost) indicators are lit up, the outdoor temperature is too cold and the unit’s
defrost cycle is activated in order to defrost the unit.
The unit changes
from COOL/HEAT
mode to FAN mode
The unit may change its setting to prevent frost from forming on the unit. Once
the temperature increases, the unit will start operating in the previously selected
mode again.
The set temperature has been reached, at which point the unit turns o the com-
pressor. The unit will continue operating when the temperature uctuates again.
The indoor unit
emits white mist
In humid regions, a large temperature dierence between the room’s air and the
conditioned air can cause white mist.
Both the indoor and
outdoor units emit
white mist
When the unit restarts in HEAT mode after defrosting, white mist may be emitted
due to moisture generated from the defrosting process.
The indoor unit
makes noises
A rushing air sound may occur when the louver resets its position.
A squeaking sound is heard when the system is OFF or in COOL mode. The noise
is also heard when the drain pump (optional) is in operation.
A squeaking sound may occur after running the unit in HEAT mode due to ex-
pansion and contraction of the unit’s plastic parts.
Both the indoor unit
and outdoor unit
make noises
Low hissing sound during operation: This is normal and is caused by refrigerant
gas owing through both indoor and outdoor units.
Low hissing sound when the system starts, has just stopped running, or is de-
frosting: 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.
Common Issues
The following problems are not a malfunction and in most situations will not require repairs.