10
Troubleshooting Information
For detailed service information refer to the Remote Condensing Unit Service manual.
NOTICE
Units with rotary or reciprocating compressors and non-bleed TXV’s
require a Hard Start Kit.
Complaint
System
Operating
Pressures
POSSIBLE CAUSE
DOTS IN ANALYSIS
GUIDE INDICATE
"POSSIBLE CAUSE"
SY
M
PT
O
M
S
y
st
e
m
w
il
l n
o
t st
a
rt
C
o
m
p
re
s
s
or
w
ill
no
t s
tar
t
-
fa
n
r
u
ns
C
o
m
p
. an
d
C
o
nd
. F
a
n
w
il
l n
o
t
s
ta
rt
E
va
p
o
rat
o
r f
an w
ill
n
o
t s
tar
t
C
o
nde
n
s
e
r f
an w
ill
n
o
t
s
tar
t
C
om
p
res
sor
r
u
n
s
-
g
oe
s
of
f o
n
ov
er
lo
ad
C
om
p
re
s
s
or
c
yc
le
s
o
n ov
er
lo
ad
S
y
s
te
m
r
u
n
s
co
n
tin
u
o
u
s
ly -
li
tt
le
c
o
o
lin
g
/h
tg
T
o
o
c
o
ol
a
nd
t
h
en
t
oo
w
a
rm
N
o
t c
oo
l
e
n
o
u
gh
on
w
a
rm
da
y
s
C
e
rt
a
in
ar
ea
s
t
o
o
c
o
ol
, o
the
rs
t
oo
w
a
rm
C
om
p
res
sor
i
s
no
is
y
S
y
s
te
m
r
uns
-
bl
o
w
s c
o
ld
a
ir
i
n
he
a
ti
ng
U
n
it w
ill
n
o
t t
e
rm
in
a
te
d
e
fr
o
st
Un
it
wi
ll n
o
t d
e
fr
o
s
t
Lo
w
s
uc
tion
p
res
s
ur
e
Lo
w
h
e
ad
p
res
s
ur
e
H
ig
h
s
u
c
ti
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pr
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re
H
ig
h
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a
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pr
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re
Test Method
Remedy
Power Failure
•
Test Voltage
Blown Fuse
•
• •
Inspect Fuse Size & Type
Unbalanced Power, 3PH
•
• •
Test Voltage
Loose Connection
•
•
•
Inspect Connection - Tighten
Shorted or Broken Wires
• • • • • •
Test Circuits With Ohmmeter
Open Fan Overload
• •
Test Continuity of Overload
Faulty Thermostat
•
• •
•
Test Continuity of Thermostat & Wiring
Faulty Transformer
•
•
Check Control Circuit with Voltmeter
Shorted or Open Capacitor
•
• • • •
Test Capacitor
Internal Compressor Overload Open
•
♦
Test Continuity of Overload
Shorted or Grounded Compressor
•
•
Test Motor Windings
Compressor Stuck
•
• •
♦
Use Test Cord
Faulty Compressor Contactor
•
• •
Test Continuity of Coil & Contacts
Faulty Fan Relay
•
Test Continuity of Coil And Contacts
Open Control Circuit
•
Test Control Circuit with Voltmeter
Low Voltage
•
• •
Test Voltage
Faulty Evap. Fan Motor
•
•
♦
Repair or Replace
Shorted or Grounded Fan Motor
•
•
Test Motor Windings
Improper Cooling Anticipator
•
•
Check Resistance of Anticipator
Shortage of Refrigerant
• •
♦
• •
Test For Leaks, Add Refrigerant
Restricted Liquid Line
• •
• •
•
Remove Restriction, Replace Restricted Part
Open Element or Limit on Elec. Heater
♦
♦
Test Heater Element and Controls
Dirty Air Filter
•
• •
•
♦
Inspect Filter-Clean or Replace
Dirty Indoor Coil
•
• •
•
♦
Inspect Coil - Clean
Not enough air across Indoor Coil
•
• •
•
♦
Check Blower Speed, Duct Static Press, Filter
Too much air across Indoor Coil
♦
•
Reduce Blower Speed
Overcharge of Refrigerant
• •
•
♦
• •
Recover Part of Charge
Dirty Outdoor Coil
• •
•
♦
•
Inspect Coil - Clean
Noncondensibles
•
•
♦
•
Recover Charge, Evacuate, Recharge
Recirculation of Condensing Air
•
•
•
Remove Obstruction to Air Flow
Infiltration of Outdoor Air
•
• •
Check Windows, Doors, Vent Fans, Etc.
Improperly Located Thermostat
•
•
Relocate Thermostat
Air Flow Unbalanced
•
•
Readjust Air Volume Dampers
System Undersized
•
•
Refigure Cooling Load
Broken Internal Parts
•
♦
Replace Compressor
Broken Valves
•
•
• •
Test Compressor Efficiency
Inefficient Compressor
•
♦
• •
Test Compressor Efficiency
Wrong Type Expansion Valve
• • •
•
• •
♦
Replace Valve
Expansion Device Restricted
• • •
•
• •
•
Remove Restriction or Replace Expansion Device
Oversized Expansion Valve
•
•
Replace Valve
Undersized Expansion Valve
• • •
•
•
Replace Valve
Expansion Valve Bulb Loose
•
•
Tighten Bulb Bracket
Inoperative Expansion Valve
•
•
•
Check Valve Operation
Loose Hold-down Bolts
•
Tighten Bolts
Faulty Reversing Valve
•
♦ ♦ ♦
♦ ♦ ♦
Replace Valve or Solenoid
Faulty Defrost Control
•
♦ ♦ ♦ ♦ ♦
♦
Test Control
Faulty Defrost Thermostat
♦ ♦ ♦ ♦ ♦ ♦ ♦
Test Defrost Thermostat
Flowrator Not Seating Properly
•
• •
Check Flowrator & Seat or Replace Flowrator
•
Cooling or Heating Cycle (Heat Pump)
♦
No Cooling
Unsatisfactory Cooling/Heating
Heating Cycle Only (Heat Pump)