Troubleshooting 16
2.Field Maintenance
Possible causes of trouble
Co
m
pr
ess
or
st
uc
k
Sh
or
ta
ge
o
f r
ef
rig
er
an
t
Re
st
ric
te
d
liqu
id
li
ne
Di
rt
y
ai
r
fil
te
r
Di
rt
y
ev
ap
or
at
or
c
oi
l
In
su
ffi
ci
en
t a
ir
th
ro
ug
h
ev
ap
or
at
or
c
oi
l
O
ve
rc
ha
rg
e
of
re
fr
ig
er
an
t
Di
rt
y
or
p
ar
�
all
y
bl
oc
ke
d
co
nd
en
se
r
Ai
r o
r i
nc
om
pr
ess
ib
le
g
as
in
re
fr
ig
er
an
t c
yc
le
Sh
or
t c
yc
lin
g
of
c
ond
en
sin
g
ai
r
Hi
gh
te
m
pe
ra
tu
re
c
ond
en
sin
g
m
ed
iu
m
In
su
ffi
ci
en
t c
ond
en
sin
g
m
ed
iu
m
Br
ok
en
c
om
pr
ess
or
in
te
rn
al
p
ar
ts
In
e
ffi
ci
en
t c
om
pr
ess
or
Ex
pa
ns
io
n
va
lv
e
ob
st
ru
ct
ed
Ex
pa
ns
io
n
va
lv
e
or
c
ap
ill
ar
y
tub
e
cl
os
ed
c
om
pl
et
el
y
Le
ak
in
g
po
w
er
e
le
m
en
t o
n
ex
pa
ns
io
n
va
lv
e
Poo
r i
ns
ta
lla
�
on
o
f f
ee
le
r bu
lb
He
av
y
lo
ad
c
ond
i
�
on
Loo
se
n
ho
ld
d
ow
n
bo
lts
a
nd
/
o
r s
cr
ew
s
Sh
ipp
in
g
pl
at
es
re
m
ai
n
a
�
ac
he
d
Poo
r c
ho
ic
es
o
f c
ap
ac
ity
Co
nt
ac
t o
f p
ip
in
g
w
ith
o
th
er
p
ip
in
g
or
e
xt
er
na
l p
la
te
Unit will not start
Compressor will not start but fans run
Compressor and condenser (outdoor) fan will not
start
Evaporator (indoor) fan will not start
Condenser (Outdoor) fan will not start
Unit runs, but shortly stops
Compressor short-cycles due to overload
High discharge pressure
Low discharge pressure
High suc
�
on pressure
Low suc
�
on pressure
Unit runs con
�
nuously but insu
ffi
cient cooling
Too cool
Compressor is noisy
Horizontal louver can not revolve
Test method / remedy
Re
pl
ac
e
th
e
co
m
pr
ess
or
Le
ak
te
st
Re
pl
ac
e
re
st
ric
te
d
pa
rt
Cl
ea
n
or
re
pl
ac
e
Cl
ea
n
co
il
Ch
ec
k
fa
n
Ch
an
ge
c
ha
rg
ed
re
fr
ig
er
an
t v
ol
um
e
Cl
ea
n
co
nd
en
se
r o
r r
em
ov
e
ob
st
ac
le
Pu
rg
e,
e
va
cu
at
e
and
re
ch
ar
ge
Re
m
ov
e
ob
st
ru
c
�
on
to
a
ir
fl
ow
Re
m
ov
e
ob
st
ru
c
�
on
in
a
ir
or
w
at
er
fl
ow
Re
m
ov
e
ob
st
ru
c
�
on
in
a
ir
or
w
at
er
fl
ow
Re
pl
ac
e
co
m
pr
ess
or
Te
st
c
om
pr
ess
or
e
ffi
ci
en
cy
Re
pl
ac
e
va
lv
e
Re
pl
ac
e
va
lve
Re
pl
ac
e
va
lv
e
Fi
x
fe
el
er
bu
lb
Ch
ec
k
he
at
lo
ad
Ti
gh
te
n
bo
lts
o
r s
cr
ew
s
Re
m
ov
e
th
em
Ch
oo
se
A
C
of
la
ge
r c
ap
ac
ity
o
r a
dd
th
e
nu
m
be
r o
f A
C
Re
c
�
fy
p
ip
in
g
so
a
s n
ot
to
c
on
ta
ct
e
ac
h
ot
he
r o
r w
ith
e
xt
er
na
l
pl
at
e
Refrigerant Circuit
Others
