34 Room Air Conditioner
Troubleshooting Guide
COMPLAINT
CAUSE
REMEDY
Check the TEMP control. If not at the lowest num-
ber, set TEMP control to this setting and restart
the unit.
Check the continuity of the thermistor. Replace the
thermistor if the circuit is open.
Check the position of knob If not at the coldest set-
ting, advance the knob to this setting and restart unit.
Check continuity of the thermostat. Replace thermo-
stat if circuit is open.
Check the capacitor.
Replace if not within ±10% of manufacturers rat-
ing. Replace if shorted, open, or damaged.
Check the compressor for open circuit or ground. If
open or grounded, replace the compressor.
Check the compressor overload, if externally
mounted. Replace if open. (If the compressor tem-
perature is high, remove the overload, cool it, and
retest.)
Check the voltage.
If not within limits, call an electrician.
Check overload, if externally mounted.
Replace if open. (If the compressor temperature is
high, remove the overload, cool, and retest.)
If not running, determine the cause. Replace if
required.
Remove the cabinet. inspect the interior surface of
the condenser; if restricted, clean carefully with a
vacuum cleaner (do not damage fins) or brush.
Clean the interior base before reassembling.
If condenser fins are closed over a large area on
the coil surface, head pressures will increase,
causing the compressor to overload. Straighten
the fins or replace the coil.
Test capacitor.
Check the terminals. If loose, repair or replace.
Check the system for a restriction.
If restricted, clean of replace.
Close if open.
Determine if the unit is properly sized for the area
to be cooled.
Check the set screw or clamp. If loose or missing,
correct. If the turbo or fan is hitting air guide,
rearrange the air handling parts.
Remove the cabinet carefully and rearrange tubing
not to contact cabinet, compressor, shroud, and
barrier.
Thermistor
Thermostat
Capacitor (Discharge
capacitor before servicing.)
Compressor
Overload
Voltage
Overload
Fan motor
Condenser air flow restric-
tion
Condenser fins (damaged)
Capacitor
Wiring
Refrigerating system
Air filter
Exhaust damper door
Unit undersized
Turbo or fan
Copper tubing
Compressor will not run,
but fan motor runs.
Compressor cycles on
overload.
Compressor cycles on
overload.
Compressor cycles on
overload.
Insufficient cooling or heat-
ing
Excessive noise
Summary of Contents for LWC121CGMK0
Page 39: ...Service Manual 39 Memo ...
