14
Problem
Possible Cause
Action
Unit does not run
Fuse blown or circuit tripped
Replace fuse, reset breaker. If repeats, check fuse
or breaker size. Check for shorts in unit wiring &
components
Power cord not plugged in
Plug it in
System switch in "OFF" position
Set switch correctly
Inoperative system switch
Test for continuity in each switch position
Loose or disconnected wiring at switch or other
components
Check wiring & connections. Reconnect per wiring
diagram
Problem
Possible Cause
Action
Evaporator coil
freezes up
Dirty fi lter
Clean as recommended in Owner's Manual
Restricted airfl ow
Check for dirty or obstructed coil. Use pressure
wash or biodegradable cleaning agent to clean
Inoperative t-stat
Test for shorted t-stat or stuck contacts
Short of refrigerant
De-ice coil & check for leak
Inoperative fan motor
Test fan motor & replace if inoperative
Partially restricted capillary tube
De-ice coil. Check temp. differential (delta T) across
coil. Touch test coil return bends for same temp.
Test for low running current
Problem
Possible Cause
Action
Compressor runs
continually & does not
cycle off
Excessive heat load
Unit undersized. Test cooling performance & replace
with larger unit if needed
Restriction in line
Check for partially iced coil & check temperature
split across coil
Refrigerant leak
Check for oil at silver soldered connections. Check
for partially iced coil. Check split across coil. Check
for low running amperage
T-stat contacts stuck
Check operation of t-stat. Replace if contacts
remain closed.
T-stat incorrectly wired
Refer to appropriate wiring diagram
Problem
Possible Cause
Action
T-stat does not turn
unit off
T-stat contacts stuck
Disconnect power to unit. Remove cover of t-stat &
check if contacts are stuck. If so, replace t-stat
T-stat set at coldest point
Turn to higher temp. setting to see if unit cycles off
Incorrect wiring
Refer to appropriate wiring diagrams
Unit undersized for area to be cooled
Refer to industry standard sizing chart
Cooling Only Room Air Conditioners: Troubleshooting Tips
