RT-SVX069A-EN
35
After approximately 30 seconds, turn the “Mode”
selection switch to the desired mode, i.e. Heat, Cool or
Auto.
Method 2
To reset the system at the unit, cycle the unit power by
turning the disconnect switch “Off” and then “On”.
Table 15.
Troubleshooting chart
Symptom
Possible Cause
Remedy
Unit will not run
Power off or loose electrical connection
Check for correct voltage at compressor contactor in
control box
Thermostat out of calibration-set too high
Reset
Failed contactor
Check for 24 volts at contactor coil - replace if contacts are
open
Blown fuses
Replace fuses
Transformer defective
Check wiring - replace transformer
Interconnecting low voltage wiring damaged
Replace thermostat wiring
Condenser fan runs, compressor
doesn't
Run or start capacitor failed (single phase only)
Replace
Loose connection
Check for correct voltage at compressor - check and
tighten all connection
Compressor stuck, grounded or open motor
winding open internal overload
Wait at least 2 hours for overload to reset. If still open,
replace the compressor.
Low voltage condition
Determine cause and correct. At compressor terminals,
voltages must be within 10% of rating plate volts when
unit is operating.
Insufficient cooling
Improperly sized unit
Recalculate load
Improper airflow
Check - should be approximately 400 CFM per ton.
Incorrect refrigerant charge
Charge per procedure attached to unit service panel.
Air, non-condensible or moisture in system
Recover refrigerant, evacuate & recharge, add filter drier
Incorrect voltage
Determine cause and correct. At compressor terminals,
voltages must be within 10% of rating plate volts when
unit is operating.
Compressor short cycles
Incorrect voltage
At compressor terminals, voltage must be ±10% or
nameplate marking when unit is operating.
Defective overload protector
Replace - check for correct voltage
Refrigerant undercharge
Add refrigerant
Compressor operates
continuously
Dirty air filter
Replace filter
Unit undersized for load
Decrease load or increase unit size
Thermostat temperature set too low
Reset thermostat
Low refrigerant charge
Locate leak, repair, and recharge
Air in system
Recover refrigerant, evacuate system, and recharge
Outdoor coil dirty or restricted
Clean coil or remove restriction
Registers sweat
Low evaporator airflow
Increase speed of blower or reduce restriction - replace air
filter
High head-low vapor pressure
Restriction in liquid line, expansion device or filter
drier
Remove or replace defective component
Flow check piston size too small
Change to correct size piston
Incorrect capillary tubes
Change coil assembly
TXV does not open
Replace TXV
High head-high or normal vapor
pressure - Cooling mode
Dirty condenser coil
Clean coil
Refrigerant overcharge
Correct system charge
Condenser fan not running
Repair or replace
Air or non-condensible in system
Recover refrigerant, evacuate & recharge
Low head-high vapor pressures
Defective compressor valves
Replace compressor
Incorrect capillary tubes
Replace coil assembly
