COOLING ONLY ROOM AIR CONDITIONERS: TROUBLESHOOTING TIPS
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Water “spitting”
into room
Sublimation:
When unconditioned saturated,
outside air mixes with conditioned
air, condensation forms on the
cooler surfaces
Ensure that foam gaskets are installed in
between window panes & in between the
unit & the sleeve. Also, ensure that fresh
air/exhaust vents (on applicable models) are in
the closed position & are in tact
Downward pitch of installation is
too steep towards back of unit
Follow installation instructions to ensure that
downward pitch of installed unit is no less than
1/4” & no more than 3/8”
Restricted coil or dirty fi lter
Clean & advise customer of periodic cleaning
& maintenance needs of entire unit
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Excessive
moisture
Insuffi cient air circulation thru area
to be air conditioned
Adjust louvers for best possible air circulation
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Inadequate vapor barrier in building
structure, particularly fl oors
Advise customer
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T-stat or
thermistor
short cycles
Defective thermistor Replace thermistor or electronic control board
T-stat differential too narrow Replace t-stat
Plenum gasket not sealing,
allowing discharge air to short
cycle t-stat
Check gasket. Reposition or replace as
needed
Restricted coil or dirty fi lter
Clean & advise customer of periodic cleaning
& maintenance needs of entire unit
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Prolonged off
cycles (automatic
operation)
Heat anticipator (resistor) wire
disconnected at t-stat or system
switch
Refer to appropriate wiring diagram
Heat anticipator (resistor) shorted or
open
Disconnect plus from outlet. Remove resistor
from bracket. Insert plug & depress “COOL”
& “FAN AUTOMATIC” buttons. Place t-stat to
warmest setting. Feel resistor for temperature.
If no heat, replace resistor
Partial loss of charge in t-stat bulb
causing a wide differential
Replace t-stat
Defective thermistor Replace thermistor or electronic control board
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Outside water
leaks
Evaporator drain pan cracked or
obstructed
Repair, clean or replace as required
Water in compressor area
Detach shroud from pan & coil. Clean &
remove old sealer. Reseal, reinstall & check
Obstructed condenser coil
Use pressure wash or biodegradable cleaning
agent to clean
Fan blade/slinger ring improperly
positioned
Adjust fan blade to 1/2” of condenser coil fi n
pack
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