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Troubleshooting
This Troubleshooting Chart is not prepared to replace the training required for a
professional refrigeration service person, not is it comprehensive
Complaint Possible
Causes
Response
1. Unit not
running
a. Power cord unplugged
b. No power to unit
c. Setting higher than ambient
temperature
d. Differential too high
e. Incorrect or loose wirings
f. Low
voltage
g. Defrost
light
blinking
h. Compressor light blinking
a. Check for power cord plug
b. Check power at receptacle & fuses
c. Lower
temperature
setting
d. Decrease the value as to 4
°
F
e. Check all wirings and connections
f.
Contact an authorized electrician
g. Unit is under defrost mode
h. Unit waits for anti-short cycle delay
2. Cabinet
temperature
high, unit
stopping
and starting
with short
running time
a.
air sensor touching the
evaporator coil, displaying
temperature ok
b. Short circuit of air flow between
supply and return air
c. Setting too high
d. Failed temperature controller
and thermistor
a. Move the air sensor away from the
evaporator
b. Deflect the supply air down
c. Lower
setting
d. Call service for diagnosis
3. Temperature
high,
compressor
stopping
and starting
but very
short
running time
a. Incorrect
voltage
b. Failed
thermistor
c. Failed
components
d. Improper
condenser
airflow
e. Dirty
condenser
f.
Overcharge of refrigerant
g. Discharge or suction pressure
too high
a. Check for voltage
b. Check thermistor by placing it in ice
water and measuring resistance
c. Check compressor windings, start
relay and overload protector.
d. Check for condenser fan
e. Clean
condenser
f.
Call service for removing refrigerant
g. Call service for OEM information
4. Temperature
high or not
cooling and
running
continually;
“HA” alarm
blinking and
beeping
a. Improper room insulation & seal
b. Room too large
c. Ambient temperature too high
d. Exhaust restricted
e. Malfunctioning
fans
f.
Improper evaporator or
condenser airflow
g. Dirty
Condenser
h. Iced
evaporator
i. Refrigeration
system
restriction
j. Refrigerant
leak
k. Undercharge or overcharge
a. Check for insulation, gasket and
door opening
b. Check for excessive size
c. Check for installation location
d. Leave minimum required clearance
for the exhaust side and leave
minimum required clearance for the
fresh air intake side
e. Check for both evaporator and
condenser fans
f. Check for air restrictions, air short-
circulation, grille directions
g. Clean
condenser
h. Defrost and reset temperature
i.
Call service for checking
restrictions
j. Call service for checking loss of
refrigerant
k. Call service to add or remove
refrigerant
