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.
Compressor Stuck
System
Operating
Pressures
POSSIBLE CAUSE
DOTS IN ANALYSIS
GUIDE INDICATE
"POSSIBLE CAUSE"
SY
MPT
O
M
Sy
st
em
w
ill
no
t st
ar
t
C
o
m
p
re
ss
o
r
wi
ll n
o
t s
ta
rt
-
f
an
ru
n
s
C
o
m
p
. a
n
d C
o
n
d
. F
an w
ill
no
t
st
ar
t
E
vap
o
rat
o
r f
an
w
ill
n
o
t
start
C
o
n
d
e
n
se
r f
an w
ill
not
st
ar
t
C
o
m
p
re
ss
o
r
ru
n
s -
g
o
e
s o
ff
o
n
o
ve
rl
o
ad
C
o
m
p
re
ss
o
r
cy
cl
e
s o
n
o
ve
rl
o
ad
Sy
st
em
r
u
ns c
o
n
ti
nuo
usl
y -
li
tt
le
c
o
ol
in
g/
ht
g
T
o
o
c
o
o
l an
d
th
en
to
o
w
arm
N
o
t c
o
o
l e
n
ou
gh
on
wa
rm
d
ay
s
Cer
tai
n
ar
eas t
o
o
c
o
o
l, o
th
e
rs to
o
w
ar
m
C
o
m
p
re
ss
o
r i
s
n
o
is
y
Sy
st
em
r
u
n
s - b
lo
w
s c
o
ld
a
ir
in
h
e
at
in
g
Un
it
wi
ll no
t t
e
rm
in
at
e
d
e
fr
o
st
Un
it
wi
ll no
t d
e
fr
os
t
Lo
w s
u
ct
io
n
p
res
su
re
Lo
w
h
ead
p
ressu
re
H
ig
h
suc
ti
o
n pr
es
sur
e
Hi
gh
h
ead
p
ressu
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)
♦
COOLING/HP ANALYSIS CHART
No Cooling
Unsatisfactory Cooling/Heating
Heating Cycle Only (Heat Pump)
