Friedrich 2007 - Manual (Page 18)

18
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