Carrier 42QH30-H Service Maintenance Manual page 22

TROUBLE CHART (Cont.)
TROUBLE
Air conditioner is not supplying enough
heating.
A slight mist is emitted from the indoor
unit during cooling
A slight whistling noise is heard when is
heard when the air conditioner starts or
stops.
Water vapor (mist) emanating from the
outdoor unit.
Unpleasant smells coming from the indoor
unit.
Strange noises coming from the indoor
unit.
Starting in heating mode for heat pump
systems
Timer Led is Blinking
Power led is blinking
REASON
Air flow cannot circulate freely
Dirty filters reduce air quantity circulating. Clean air filters
Doors and/or windows are open.
Fan speed has been set to "Low"
Air flow direction is not correct
Selected temperature is Lower than the
room temperature in the heating mode.
The cool air from the indoor unit is
coming into contact with the room air.
This is due to the refrigerant beginning to
circulate or an adjustment of the
refrigerant pressures.
It is normal in heat pump operation, when
defrost is automatically activated.
Unpleasant smells can be caused by
substances accumulated in the air filters
Occasionally the indoor unit can emit
some strange short noises during
operation or when it has stopped.
These are generally due to the of
temperature changes on the plastic parts.
If the system starts at low ambient
temperatures, it takes a little while to
reach a comfortable room temperature.
When the system is started by the
remote control, it emits a signal beep, but
the louvre does not swing and the fan
does not run until the operating
temperature has been reached.
Faulty return air sensor
Faulty return indoor coil sensor
Faulty return outdoor coil sensor
Compressor overheat
Anti overheat
Low ambient
21
ACTION
Remove obstructions.
Close doors and windows
Set fan speed at high speed.
Adjust airflow direction as per the mode
chosen.
Correct selected temperature.
Normal operation
Normal operation
Normal operation
Switch the system OFF and contact an
authorized service center to have the filters
cleaned.
Restart unit in the ventilation (fan only) mode
and open windows to change room air.
Normal operation
Normal operation
Determine reason and replace
Determine reason and replace
Determine reason and replace
Determine reason and correct
Determine reason and correct
Determine reason and correct