SERVICING
23
Com plaint
Sys te m
Ope r ating
Pre s s ure s
POSSIBLE CAUSE
DOTS IN ANALYSIS
GUIDE INDICATE
"POSSIBLE CAUSE"
SYM
PT
O
M
S
y
s
tem w
ill
not
s
tar
t
C
o
m
p
re
s
s
o
r w
ill
n
o
t s
ta
rt
-
f
a
n
ru
n
s
C
o
mp.
and
C
ond.
F
an w
ill
not
s
tar
t
E
v
ap
or
at
or
f
a
n
w
ill
not
s
tar
t
C
o
nde
ns
er
f
a
n
w
ill
not
s
tar
t
C
o
m
p
re
s
s
o
r
ru
n
s
-
g
o
e
s
o
ff
o
n
o
v
e
rl
o
a
d
C
o
m
p
re
sso
r cycl
e
s
o
n
o
v
e
rl
o
a
d
S
y
s
tem
ru
ns
c
ont
in
uous
ly
-
li
tt
le
c
ool
ing/h
tg
T
oo c
ool
and the
n
t
o
o w
a
rm
N
o
t c
o
ol
enou
gh o
n
w
a
rm
day
s
C
e
rt
ai
n ar
ea
s
t
o
o c
o
ol
, ot
her
s
t
oo wa
rm
C
o
m
p
re
s
s
o
r i
s
n
o
is
y
S
y
s
tem r
u
ns
-
bl
ow
s
c
o
ld
ai
r
in
h
eati
n
g
Un
it wi
ll n
o
t te
rm
in
a
te
d
e
fr
os
t
Un
it wi
ll n
o
t d
e
fr
o
s
t
L
o
w
su
ct
io
n
p
re
ssu
re
Low
head pr
es
s
u
re
H
ig
h
su
ct
io
n
p
re
ssu
re
H
igh head pr
es
s
u
re
Te st Me thod
Re me dy
S
ee S
e
rv
ice P
ro
ced
u
re R
e
f.
Pow er Failure
•
Test V oltage
S-1
Blow n Fuse
•
• •
Inspect Fuse Size & Type
S-1
Unbalanced Pow er, 3PH
•
• •
Test V oltage
S-1
Loose Connection
•
•
•
Inspect Connection - Tighten
S-2, S-3
Shorted or Broken Wires
• • • • • •
Test Circuits With Ohmmeter
S-2, S-3
Open Fan Overload
• •
Test Continuity of Overload
S-17A
Faulty Thermostat
•
• •
•
Test continuity of Thermostat & Wiring
S-3
Faulty Transf ormer
•
•
Check control circuit w ith voltmeter
S-4
Shorted or Open Capacitor
•
• • • •
Test Capacitor
S-15
Internal Compressor Overload Open
•
♦
Test Continuity of Overload
S-17A
Shorted or Grounded Compressor
•
•
Test Motor Windings
S-17B
Compressor Stuck
•
• •
♦
Use Test Cord
S-17D
Faulty Compressor Contactor
•
• •
Test continuity of Coil & Contacts
S-7, S-8
Faulty Fan Control
•
Test continuity of Coil A nd Contacts
S-7, S-9
Open Control Circuit
•
Test Control Circuit w ith V oltmeter
S-4
Low V oltage
•
• •
Test V oltage
S-1
Faulty Evap. Fan Motor
•
•
♦
Repair or Replace
S-16
Shorted or Grounded Fan Motor
•
•
Test Motor Windings
S-16A ,D
Improper Cooling A nticipator
•
•
Check resistance of A nticipator
S-3B
Shortage of Ref rigerant
• •
♦
• •
Test For Leaks, A dd Ref rigerant
S-101,103
Restricted Liquid Line
• •
• •
•
Remove Restriction, Replace Restricted Part
S-112
Open Element or Limit on Elec. Heater
♦
♦
Test Heater Element and Controls
S-26,S-27
Dirty A ir Filter
•
• •
•
♦
Inspect Filter-Clean or Replace
Dirty Indoor Coil
•
• •
•
♦
Inspect Coil - Clean
Not enough air across Indoor Coil
•
• •
•
♦
Check Blow er Speed, Duct Static Press, Filter
S-200
Too much air across Indoor Coil
•
♦
•
Reduce Blow er Speed
S-200
Overcharge of Ref rigerant
• •
•
♦
• •
Recover Part of Charge
S-113
Dirty Outdoor Coil
• •
•
♦
•
Inspect Coil - Clean
Noncondensibles
•
•
♦
•
Recover Charge, Evacuate, Recharge
S-114
Recirculation of Condensing A ir
•
•
•
Remove Obstruction to A ir Flow
Inf iltration of Outdoor A ir
•
• •
Check Window s, Doors, V ent Fans, Etc.
Improperly Located Thermostat
•
•
Relocate Thermostat
A ir Flow Unbalanced
•
•
Readjust A ir V olume Dampers
System Undersized
•
•
Ref igure Cooling Load
Broken Internal Parts
•
♦
Replace Compressor
S-115
Broken V alves
•
•
• •
Test Compressor Ef f iciency
S-104
Inef f icient Compressor
•
♦
• •
Test Compressor Ef f iciency
S-104
Loose Hold-dow n Bolts
•
Tighten Bolts
Faulty Reversing V alve
•
♦ ♦ ♦
♦ ♦ ♦
Replace V alve or Solenoid
S-21, 122
Faulty Def rost Control
•
♦ ♦ ♦ ♦ ♦
♦
Test Control
S-24
Faulty Def rost Thermostat
♦ ♦ ♦ ♦ ♦ ♦ ♦
Test Def rost Thermostat
S-25
Flow rator Not Seating Properly
•
• •
Check Flow rator & Seat or Replace Flow rator
S-111
•
♦
No Cooling
Uns atis factory
Cooling/He ating
Cooling or He ating Cycle (He at Pum p)
He ating Cycle Only (He at Pum p)
COOLING /HEAT PUMP- SERVICE ANALYSIS GUIDE
SERVICING
