Carrier 42QH30-H Service Maintenance Manual page 20

TROUBLE SHOOTING (Cont.)
TROUBLE
Head pressure too low
Excessive section pressure
Suction pressure too low
(Low pressure control cuts-out & pilot
light for low pressure control lights off)
Outdoor fan stopped or cycling on
overload
After batteries have been placed into
the remote control, the display is not lit.
When pressing the recessed lock
adjustment button, hour figures on
display do not flash.
When pressing any button, all symbols
appear on display.
When pressing start button, unit does
not acknowledge signal with a beep.
REASON
Low refrigerant charge
Restriction in liquid tube
Indoor section air filter dirty
Reversing valve hung up or internal leak
Internal pressure relief open
Refrigerant over charged
Low refrigerant charge
Indoor unit frosted
Low indoor air or short cycling
Restriction in suction tube
Capillary or accurate restricted or ice clogged
Detective fan motor capacitor
Loose leads at fan motor
Fan motor burned out
Motor bearing sized
Batteries are exhausted or have the wrong
polarity.
Recessed button has not been pressed
correctly.
Recessed button for time setting is blocked due
to excessive pressure during use.
Remote control has been irreversibly damaged. Replace with a new one.
Main switch is OFF.
Remote control batteries are exhausted.
Remote control has not been pointed correctly
to the receiver of indoor unit.
There are obstacles (curtains, walls, etc.)
between the remote control and the indoor unit
Receiver on the indoor unit or the remote
control is under intense sun radiation.
Signal transmission is obstructed by severe
interference from an electromagnetic field.
19
ACTION
Check for leaks, repair and recharge
Remove restriction
Clear filter
Replace
Check for source and eliminate
Purge excess refrigerant
Check for leaks, repair and recharge
See next trouble
Eliminate cause, check for fan working
Locate restriction and remove
Blow refrigerant, evacuate system and
recharge
Replace
Check for cause and eliminate
Replace
Check for cause and eliminate
Replace batteries or check polarity.
Press with a round point, avoid exerting
strong pressure
Check and repair.
Switch it to ON position.
Replace batteries.
Turn remote control OFF and repeat the
operation in the correct direction.
Repeat the operation after having
removed the obstacles.
Avoid direct sun on the unit, shut curtains
or shades.
Avoid sending signals when computers or
household appliances (Food processors,
coffee makers, etc.) are operating close
by cellular or cordless telephones may
also interfere with the control.