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k. Undercharge or overcharge
l.
Air sensor contacting the evaporator
k. Call service to add or remove
refrigerant
l. Move the air sensor away from the
evaporator
4. Unit running too long or continually
a. Improper room insulation & seal
b. Exhaust restricted
c. Room too large
d. Ambient temperature higher > 90
°
F
e. Improper evaporator or condenser
airflow
f. Dirty
Condenser
g. Iced evaporator
h. Malfunctioning fans
i. Sealed
system
problem
j. Undercharge or overcharge
a. Check for insulation, gasket and door
opening
b. Leave minimum 3 feet clearance for
the exhaust side and leave minimum
1 foot clearance for the fresh air
intake side
c. Check for excessive size or increase
setting
d. Check for installation location or
increase setting
e. Check for air restrictions
f. Clean
condenser
g. Defrost and reset temperature
h. Check for both evaporator and
condenser fans
i. Call service for checking loss of
refrigerant or restrictions
j. Call service to add or remove
refrigerant
5. Unit stopping and starting but short running time
a. Incorrect temperature setting
b. Incorrect
voltage
c. Failed
thermistor
d. Failed
components
e. Improper
condenser
airflow
f. Dirty
condenser
g. Overcharge of refrigerant
h. Discharge or suction pressure too
high
a. Set 55 to 60
°
F
b. Check for voltage
c. Check thermistor by placing it in ice
water and measuring resistance
d. Check compressor windings, start
relay and overload protector.
e. Check for condenser fan
f. Clean
condenser
g. Call service for removing refrigerant
h. Call service for OEM information
6. No cooling but unit running
a. Evaporator airflow restriction
b. Refrigerant
leakage
c. Refrigeration
system restriction
a. Check for airflow through evaporator
b. Check for loss of refrigerant
c. Call service for checking restrictions
7. Evaporator Icing
a. Evaporator air flow restriction
b. Unit not stopping due to air leak,
high ambient temperature or low
setting
c. Low ambient temperature
d. Bad thermostat or sensor
e. Refrigerant
leaking
f. Expansion valve or liquid line
restriction
a. Check for fans
b. Check for seal, door opening,
ambient temperature and setting
c. Defrost the unit
d. Check for thermostat and sensor
e. Check for sealed system leakage
f.
Check for low side pressure
8. Circuit tripping
