Wiring and Controls
Loose wiring connections, or control contactor defective.
Unit Short
Cycles
(Continued)
Compressor Overload
Defective
compressor
overload, check and replace ifnecessary
If the
compressor
runs too hot, it may be due to a insufficient
refrigerant
charge.
Water
Lack of sufficient
pressure,
temperature, and/or
quantity
of water,
Unit
Undersized
Recalculate heat
gains
or
losses for
space to be conditioned.
If
excessive, rectify by adding insulation, shading, etc.
Check for leaks in ductwork or introduction
of
ambient air through
doors and windows.
Improperly located thermostat
(e.g.
near kitchen), inaccurately
sensing the comfort
level in the living area.
Check
anticipator
setting.
Loss of Conditioned Air
by Leaks
Thermostat
Airflow Lack of adequate airflow or
improper
distribution of air. Check
the
motor speed or duct sizing. Check the
filter, it
should be
inspected
every
month and changed if dirty. Remove or add
resistance
accordingly.
Refrigerant Charge
Low
on
refrigerant
charge
causing inefficient operation. Adjust only
after checking CFM
and GPM.
Compressor
Checkfor defective compressor.
Ifdischarge
pressure
is too low
and
suction
pressure
is too high, compressor
is not
pumping
properly.
Replace compressor.
Reversing Valve Defective
reversing valve creating blpass of
refrigerant from
discharge to suction side
of compressor. When
it is necessary to
replace the reversing
valve, wrap it with a wet cloth and direct
heat
away. Excessive
heat
can damage
the valve.
Insufficient
cooling or
heating.
Desuperheater
The desuperheater circuit
(in-line
fuse) should be disconnected
during cold
weather to allow full heating load to the
house.
Dirty Filter
Check filter. Clean or
replace if found dirty
Thermostat Improperly Set Check
if thermostat
is
set at corect
temperature.
Defective Thermostat Check thermostat operation.
Replace if found defective.
Incorrect Wiring Check
for
broken,
loose, or incorrect
wires
Check blower motor
in
one of
the other switch
positions.
ff it does
not
operate,
check for open overload.
If
overload
is open and
motor is not overheated,
replace it.
unir
will not
operate on
"heating"
Blower Motor Defective
Defective solenoid
valve will not energize.
Replace solenoid coil.
Reversing
Valve
Does Not
Shift
Unit does
not
cool
(Heats
only)
Reversing
Valve
Does Not
Shift, the Valve is Stuck
The solenoid
valve is de-energized due to
miswiring at the unit or
thermostat--correct
wiring.
Replace if valve is tight or
frozen
and
will not move. Switch from
heating
to cooling
a few times to
loosen
valve.
Compressor
Make sure the compressor
is not in direct contact
with the base or
sides of the cabinet.
Cold surroundings can
cause liquid slugging.
Increase ambient
tempgrafure.
Blower and Blower Motor
Blower wheel hitting the casing.
Adjust for clearance and
alignment.
Bent blower, check and
replace if damaged. Loose
blower
wheel on shaft, check and tighten.
Defective bearings,
check and replace.
Noisy
Operation
Contactors
A
clattering
or humming noise in the contactor could
be due to
control
voltage less than 18 volts. Check
for low
supply
voltage,
low transformer output, or extra
long runs of thermostat
wires.
If the contacts are
pitted
or corroded
,
or coil is defective,
repair
or replace.
l4
PROBLTM POSSIBLE CAU,S3
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