33
Table 10—
Troubleshooting Chart
SYMPTOM
CAUSE
REMEDY
Compressor and outdoor fan
will not start
Power failure
Call power company
Fuse blown or circuit breaker tripped
Replace fuse or reset circuit breaker
Defective contactor, transformer, control relay, or high--
pressure, loss--of--charge or low--pressure switch
Replace component
Insufficient line voltage
Determine cause and correct
Incorrect or faulty wiring
Check wiring diagram and rewire correctly
UI setting too low/too high
Reset UI setting
DO NOT bypass this compressor time
delay–wait for 5 minutes until time--delay
relay is de--energized
Units have a 5--minute time delay
Compressor will not start but condenser fan
runs
Faulty wiring or circuit
Loose connections in compressor
Check wiring and repair or replace
Compressor motor burned out, seized, or
Determine cause
internal overload open
Replace compressor
Defective run capacitor, overload, or PTC (positive
temperature coefficient) thermistor
Determine cause and replace
Low input voltage (20 percent low)
Determine cause and correct
Compressor cycles (other than normally sat-
isfying) cooling/heating calls
Refrigerant overcharge or undercharge
Recover refrigerant, evacuate system, and re-
charge to capacities shown on rating plate
Defective compressor
Replace and determine cause
Insufficient line voltage
Determine cause and correct
Blocked outdoor coil
Determine cause and correct
Defective run/start capacitor, overload or start relay
Determine cause and replace
Faulty outdoor fan motor or capacitor
Replace
Restriction in refrigerant system
Locate restriction and remove
Compressor operates continuously
Dirty air filter
Replace filter
Unit undersized for load
Decrease load or increase unit size
UI temperature set too low
Reset UI setting
Low refrigerant charge
Locate leak, repair, and recharge
Air in system
Recover refrigerant, evacuate system, and re-
charge
Outdoor coil dirty or restricted
Clean coil or remove restriction
Excessive head pressure
Dirty air filter
Replace filter
Dirty indoor or outdoor coil
Clean coil
Refrigerant overcharged
Recover excess refrigerant
Air in system
Recover refrigerant, evacuate system, and re-
charge
Indoor or outdoor air restricted or air short--cycling
Determine cause and correct
Head pressure too low
Low refrigerant charge
Check for leaks, repair and recharge
Restriction in liquid tube
Remove restriction
Excessive suction pressure
High heat load
Check for source and eliminate
Reversing valve hung up or leaking internally
Replace valve
Refrigerant overcharged
Recover excess refrigerant
Suction pressure too low
Dirty air filter
Replace filter
Low refrigerant charge
Check for leaks, repair and recharge
Metering device or low side restricted
Remove source of restriction
Insufficient coil airflow
Check filter–replace if necessary
Temperature too low in conditioned area
Reset UI setting
Outdoor ambient below 55
°
F
Verify low--ambient cooling enabled in UI
Filter drier restricted
Replace
IFM does not run
Blower wheel not secured to shaft
Properly tighten blower wheel to shaft
Insufficient voltage at motor
Determine cause and correct
Power connectors not properly sealed
Connectors should snap easily; do not force
IFM operation is intermittent
Water dripping into motor
Verify proper drip loops in connector wires
Connectors not firmly sealed
Gently pull wires individually to be sure they are
crimped into the housing
48D
U
