Friedrich air conditioner troubleshooting

A vividly expressed tendency towards increase of demand for an economical climatic technique has appeared recently. The company focused its attention on provision of non-sound operation, superior air distribution, features of rational use of energy, simplified installation, and reduction of load on a service staff. It is achieved, inter alia, by application of efficient Friedrich air conditioner troubleshooting system allowing to identify any case of malfunction and determine ways of its removal.

Friedrich air conditioner troubleshooting cooling

PROBLEMPOSSIBLE CAUSETO CORRECT
Compressor does not runLow voltageCheck for voltage at compressor. 115 volt and 230
volt units will operate at 10% voltage variance
Thermostat not set cold enough
or inoperative.
Set thermostat to coldest position. Test thermostat
and replace if inoperative
Compressor hums but cuts off on
overload
Hard start compressor. Direct test compressor. If
compressor starts, add starting components
Open or shorted compressor
windings
Check for continuity and resistance
Open overloadTest overload protector and replace if inoperative
Open capacitor.Test capacitor and replace if inoperative.
Inoperative system switchTest for continuity in all positions. Replace if
inoperative
Broken, loose or incorrect wiringRefer to appropriate wiring diagram to check wiring
Fan motor
does not run
Inoperative system switch.Test switch and replace in inoperative.
Broken, loose or incorrect wiring.Refer to applicable wiring diagram.
Open Capacitor.Test capacitor and replace if inoperative.
Fan speed switch open.Test switch and replace if inoperative.
Inoperative fan motor.Test fan motor and replace if inoperative.
(Be sure internal overload has had time to
reset.)
Does not cool, or cools
only slightly
Undersized unitRefer to Sizing Charts.
Thermostat open or inoperative.Set to coldest position. Test thermostat and
replace if necessary
Dirty filterClean as recommended in Owner's Manual
Dirty or plugged condenser or
evaporator coil.
Use steam or detergents to clean
Poor air circulation in area being
cooled
Adjust discharge air louvers. Use high fan
speed.
Fresh air or exhaust air door open
on applicable models
Close doors. Instruct customer on use of
this feature
Low capacity – undercharge.Check for leak and make repair.
Compressor not pumping
properly
Check amperage draw against nameplate.
If not conclusive, make pressure test
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 and components
Power cord not plugged in.
System switch in "Off" positionSet switch correctly.
Inoperative system switchTest for continuity in each switch position.
Loose or disconnected wiring at
switch or other components
Check wiring and connections. Reconnect
per wiring diagram
Evaporator coil
freezes up.
Dirty filterClean as recommended in Owner's Manual
Restricted air flow.Check for dirty or obstructed coil - clean as re-
quired
Inoperative thermostatTest for shorted thermostat or stuck contacts.
Short of refrigerantDe-ice coil and check for leak.
Inoperative fan motorTest fan motor and replace if inoperative
Partially restricted capillary.Deice coil. Check temperature differential across
coil. Touch test coil return bends for same tem-
perature. Test for low running current
Compressor runs
continually.
Does not cycle off
Excessive heat loadUnit undersized. Test cooling performance of unit.
Replace with larger unit
Restriction in lineCheck 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.
Thermostat contacts stuckCheck operation of thermostat. Replace if con-
tacts remain closed
Thermostat incorrectly wiredRefer to appropriate wiring diagram.
Thermostat does not
turn unit off.
Thermostat contacts stuckReplace thermostat
Thermostat set at coldest pointTurn to higher temperature setting to see if the
unit cycles off
Incorrect wiring.Refer to appropriate wiring diagram
Unit undersized for area to be cooled.Refer to Sizing Chart
Compressor attempts
to start, or runs for
short periods only.
Cycles on overload
Overload inoperative. Opens too
soon
Check operation of unit. Replace overload if
system operation is satisfactory.
Compressor attempts to start before
system pressures are equalized.
Allow a minimum of two (2) minutes for pressures
to equalize before attempting to restart. Instruct
customer of waiting period
Low or fluctuating voltageCheck voltage with unit operating. Check for
other appliances on circuit. Air conditioner should
be on separate circuit for proper voltage, and be
fused separately
Incorrect wiringRefer to appropriate wiring diagram
Shorted or incorrect capacitorCheck by substituting a known good capacitor of
correct rating
Restricted or low air flow through
condenser coil.
Check for proper fan speed or blocked con-
denser
Compressor running abnormally hotCheck for kinked discharge line or restricted con-
denser. Check amperage
Thermostat does
not turn unit on
Loss of charge in thermostat bulbPlace jumper across thermostat terminals to check
if unit operates. If unit operates, replace thermo-
stat.
Loose or broken parts in thermostat.Check as above.
Incorrect wiring.Refer to appropriate wiring diagram.
Noisy operationPoorly installed unit.Refer to Installation Instructions for proper
installation
Fan blade striking chassisReposition - adjust motor mount
Compressor vibratingCheck that compressor grommets have not
deteriorated. Check that compressor mounting
parts are not missing
Improperly mounted or loose cabinet
parts.
Check assembly and parts for looseness, rubbing
and rattling.
Water leaks into
room
Evaporator drain pan overflowingClean obstructed drain trough
Condensation forming on base pan.Evaporator drain pan broken or cracked. Reseal
or replace
Poor installation resulting in rain en-
tering room
Check Installation Instructions. Reseal as re-
quired
Condensation on discharge grilles.Dirty evaporator coil - clean. Very high humidity
level.
Thermostat short
cycles
Thermostat differential too narrowReplace thermostat
Plenum gasket not sealing,
allowing discharge air to short cycle
thermostat.
Check gasket. Reposition or replace.
Restricted coil or dirty filter.Clean and advise customer of periodic cleaning of
filter
Tubular insulation missing from top of
thermostat bulb
Replace tubular insulation on bulb.
(Applicable models.)
Thermostat bulb touching thermostat
bulb support bracket
Adjust bulb bracket.
(Applicable models.)
Prolonged off-cycles.
(automatic operation)
Anticipator (resistor) wire
disconnected at thermostat or system
switch
Refer to appropriate wiring diagram
Anticipator (resister shorted or open).
(Applicable models.)
Disconnect plug from outlet. Remove resistor
from bracket. Insert plug and depress "Cool"
and "Fan - Auto (MoneySaver)" buttons. Place
thermostat to warmest setting. Feel resistor for
temperature. If no heat, replace resistor.
Partial loss of charge in thermostat
bulb causing a wide differential
Replace thermostat
Switches from
cooling to heating
Thermostat sticking.Change room thermostat.
Incorrect wiringRefer to appropriate wiring diagram.
Outside water leaks.Evaporator drain pan cracked or ob-
structed
Repair, clean or replace as required.
Water in compressor area.Detach shroud from pan and coil. Clean and
remove old sealer. Reseal, reinstall and check
Obstructed condenser coilSteam clean
Fan blade and slinger ring improperly
positioned
Adjust fan blade to 1/2" clearance from
condenser coil.
High indoor
humidity
Insufficient air circulation in air condi-
tioned area.
Adjust louvers for best possible air circulation
Oversized unitOperate in "Fan-Auto (MoneySaver)" position
Inadequate vapor barrier in building
structure, particularly floors.
Advise customer

Friedrich air conditioner troubleshooting Heating (Heat pumps)

PROBLEMPOSSIBLE CAUSETO CORRECT
No heating;
fan operates.
Thermostat settingSet thermostat to a warmer position.
Defective thermostat.Replace — do not attempt to adjust.
Compressor not operating.Check compressor wiring. Check for open inter-
nal or external overload. Check wiring.
Defective system switchTest system switch
Insufficient heatingRestricted filterClean as recommended in Owner's Manual
Outdoor thermostat.
(Applicable models.)
Check if outdoor thermostat is energizing the
heating element at its predetermined temperature
setting
Fresh air or exhaust door openCheck control setting
Fan operates in
"constant" position,
but not in "automatic"
(MoneySaver).
Inoperative system switchCheck continuity of switch.
Incorrect wiring.Check applicable wiring diagram
Temperature varies
from comfortable to
overly warm
Defective thermostatIncorrect differential setting. Replace thermostat.
Heat anticipator (resistor) shorted.
(Applicable models)
Check voltage to resistor. If voltage okay, remove
resistor from thermostat bulb block. With current
on, feel resistor for warmth. If no heat can be felt,
replace anticipator.
Room temperature
uneven.
(Heating cycle)
Heat anticipator (resistor) shorted.
(Applicable models.)
Disconnect power to unit. Remove resistor from
thermostat bulb block. Plug in unit and allow to
operate. Feel resistor for heat. If no heat is felt,
replace resistor
Wide differential — partial loss of ther-
mostat bulb charge
Replace thermostat and check
Incorrect wiringRefer to appropriate wiring diagram. Resistor is
energized during the "on" cycle of compressor or
fan
Unit will not defrostIncorrect wiring.Refer to appropriate wiring diagram
Defrost control timer motor not ad-
vancing.
Check for voltage at "TM" and "TM1" on timer. If
voltage, replace control
Defrost control out of calibrationIf outside coil temperature is 25° F or below, and
pre-selected time limit has elapsed, replace the
defrost control.
Defrost control contacts stuck.If the contacts remain closed between terminals
"2" and "3" of the defrost control after pre-selected
time interval has passed, replace control.
Defrost control bulb removed from
coil, or not making good coil contact
Reinstall and assure that good bulb to coil contact
is made
Unit does not heat
adequately
Outdoor thermostat does not cut
off compressor at the pre-selected
temperature and bring on the heating
element
Defective thermostat — replace.
Fresh air or exhaust door openCheck if operating properly. Instruct customer on
proper use of control
Dirty filterClean as recommended in Owner's Manual
Unit undersizedCheck heat rise across coil. Refer to performance
data sheet on heat rise at various outdoor ambients.
If heat rise is satisfactory, check if insulation can be
added to attic or walls
Unit cools when heat
is called for
Incorrect wiring.Refer to applicable wiring diagram
Defective solenoid coilCheck for continuity of coil
Reversing valve fails to shift.Block condenser coil and switch unit to cooling. Al-
low pressure to build up in the system, then switch to
heating. If valve fails to shift, replace valve
Inoperative system switchCheck for continuity of system switch
Cooling adequate
—heating insufficient
Heating capillary tube partially re-
stricted
Check for partially starved outer coil. Replace heating
capillary tube
Check valve leaking internallySwitch unit several times from heating to cooling.
Check temperature rise across the coil. Refer to
specification sheet for correct temperature rise
Reversing valve failing to shift com-
pletely — bypassing hot gas
De-energize solenoid coil, raise head pressure, en-
ergize solenoid to break loose. If valve fails to make
complete shift, replace valve
Compressor will not turn
off and operate on heat-
ing element only during
low outside ambients.
Outdoor thermostat.
(Applicable models.)
Refer to the heating data on applicable models for
the pre-selected temperature the compressor shuts
off and the electric element is energized
Compressor shuts
off on outdoor
thermostat but
element does
not heat.
Fuse linkCheck fuse link for continuity. If defective, replace.
Check amperage draw of element. If no amperage,
replace
Heating element shortedCheck voltage to element. If voltage is okay, check
wiring
Heat relay or heater contactor coil
open
Fan Operates
– heating element
does not come on
Heater relay or contactor coil openCheck continuity of coil.
Heater relay or contactor stuck open,
pitted or burned
Inspect, test continuity with ohmmeter.
High limit control openCheck continuity – if open, replace
Open thermal fuse.Check continuity. Check reason for failure
Open or shorted element.Check voltage across heater terminals. Check
amperage draw of heater
Loose connectionsTighten all terminals
Heating inadequateRestricted filterClean as recommended in Owner's Manual.
Cycling high limit controlControl is set to open at 155°F ± 5°F and close
at 130°F ± 8°F. If cycling prematurely, replace
control.
Exhaust or fresh air door open.Check position of fresh air door control slide.
Adjust cable if door does not close properly.
Fan operates in
"Constant" position,
but not in "Automatic"
(MoneySaver)
Fan relay contacts openCheck continuity of fan relay. NOTE: Some
models have the fan relay energized during the
heating cycle while others do not
Inoperative system switch.Check continuity between terminals "L2" and "3"
of the system switch
Loose connection.Check connections on system switch and fan
relay
Long "off" and
"on" cycles
Heat anticipator (resistor) shortedDisconnect power to unit. Remove resistor from
thermostat bulb block. Plug in unit and allow to
operate. Feel resistor for heat. If no heat is felt,
replace resistor
Defective thermostat.Replace thermostat and check operation
Fan motor does not
operate in "Constant"
or "MoneySaver"
position.
Defective motorCheck and replace.
Open or shorted capacitor.Replace capacitor and check.
Condenser fan frozen to base pan.Check if drain pan valve is open. If not, replace.
Loose connectionsCheck all connections. Check voltage to fan
motor
Cooling adequate,
heating insufficient.
Heating capillary tube partially
restricted
Check for partially starved outer coil. Replace
heating capillary tube.
Check valve leaking internallySwitch unit several times from heating to cooling.
Check temperature rise across coil. Refer to
specification sheet for correct temperature rise
Reversing valve failing to shift
completely – bypassing hot gas
De-energize solenoid coil, raise head pressure,
energize solenoid to break loose. If valve fails to
make complete shift, replace valve
Compressor will not
turn off and operate
on heating element
only during low out-
side ambients
Outdoor thermostat.
(Applicable models.)
Refer to the heating data on applicable models
for the pre-selected temperature the compressor
shuts off and the electric element is energized
Compressor shuts
off on outdoor
thermostat but,
element does not
heat.
Fuse linkCheck fuse link for continuity. If defective, replace
Heating element shortedCheck amperage draw of element. If no am-
perage, replace
Incorrect wiringCheck voltage to element. If voltage is okay,
check wiring
Heat relay or heater contactor
coil open
Defective coil. Test coil for continuity.

Troubleshooting Heating

(Cooling/Electric Models)

PROBLEMPOSSIBLE CAUSETO CORRECT
Fan operates
–heating element
does not come on
Heater relay or contactor coil openCheck continuity of coil.
Heater relay or contactor stuck
open, pitted or burned.
Inspect, test continuity with ohmmeter
High limit control open.Check continuity – if open, replace
Open Thermal fuse.Check Continuity. Check reason for failure.
Open or shorted element.Check voltage across heater terminals. Check
amperage draw of heater
Loose connections.Tighten all terminals.
Heating inadequate.Restricted filter.
Cycling high limit control
Clean as recommended in Owner's Manual.
Exhaust or fresh air door openCheck position of fresh air door control slide.
Adjust cable if door does not close properly
Fan operates in
the "Constant"
position, but not
in "Automatic."
(MoneySaver)
Fan relay contacts openCheck continuity of fan relay. NOTE: Some
models have the fan relay energized during the
heating cycle while others do not.
Inoperative system switchCheck continuity between terminals "L2" and "3"
of the system switch
Loose connection.Check connections on system switch and fan
relay
Long "off" and "on"
cycles.
Heat anticipator (resistor) shortedDisconnect power to the unit. Remove the resis-
tor from the thermostat bulb block. Plug in the
unit and allow to operate. Feel the resistor for
heat. If no heat is felt, replace the resistor
Defective thermostatReplace thermostat and check operation
Fan motor does not
operate in "Constant"
or "MoneySaver"
position
Defective motorCheck and replace
Open or shorted capacitor.Replace capacitor and check.
Condenser fan frozen to base panCheck if drain pan valve is open, if not, replace
Loose connections.Check all connections. Check voltage to fan motor
Element does
not heat
Fuse link.Check fuse link for continuity.
If defective, replace
Heating element shortedCheck amperage draw of element.
If no amperage, replace
Incorrect wiringCheck voltage to element. If voltage is okay,
check wiring
Heat relay or heater contactor coil
open
Defective coil. Test coil for continuity.