25
25 Troubleshooting (Sheet 4 of 4)
Comfor
tNet™
Ther
mostat Onl
y
S
y
m
p
toms of
A
b
normal Ope
ration
(Legac
y
& Comfor
tNet™ Thermostat)
7-Segment LED
Codes
Characters
Wi
ll
A
lter
nate
Faul
t Desc
ri
pti
on
Messa
ge Code
Possible
Causes
Correct
iv
e A
c
tions
Notes & Cauti
ons
x
Air hand
ler
blow
er fails to
opera
te
.
x
Inte
grated con
trol
module
LED
displa
y
prov
ides
indi
cated error code
.
x
ComfortNe
t™
ther
mosta
t “Call for
Serv
ice” icon il
lumi
nated
.
x
ComfortNe
t™
ther
mosta
t
scroll
s
“Check Air
Handle
r”
message
.
b5
x
Circula
tor
blow
er
m
o
tor
fail
s
to
s
tar
t
10
c
o
ns
e
c
ut
iv
e
t
im
e
s
.
MT
R
LCKD
ROTOR
b5
x
Obstru
ction
in
circu
lator
blow
er housing
.
x
Seized
circulato
r bl
ow
er motor
bearings.
x
Failed
circulato
r blo
w
er motor.
x
Check
circulator bl
ow
er for
obstruction
s.
Remov
e and
repair/r
epla
ce w
heel/moto
r i
f
nece
ssa
ry
.
x
Check
circulator bl
ow
er motor
shaf
t ro
tatio
n and
m
o
tor.
Replace
motor
i
f ne
cessary
.
x
Turn pow
er OFF pri
or to
repair
x
Replace
motor
w
ith
corre
ct rep
lacemen
t
part.
x
Replace
w
heel w
ith
corre
ct rep
lacemen
t
part.
x
Air hand
ler
blow
er fails to
opera
te
.
x
Inte
grated con
trol
module
LED
displa
y
prov
ides
indi
cated error code
.
x
ComfortNe
t™
ther
mosta
t “Call for
Serv
ice” icon il
lumi
nated
.
x
ComfortNe
t™
ther
mosta
t
scroll
s
“Check Air
Handle
r”
message
.
b6
x
Circula
tor
blow
er
motor
shu
ts dow
n for
ov
er or under
v
o
ltage
condi
tion
.
x
Circula
tor
blow
er
motor
shu
ts dow
n d
ue
to ov
er
tempera
ture
condi
tion
on
pow
er
module.
MO
T
O
R
VOLTS
b6
x
High AC lin
e v
o
ltag
e to
air
handler blow
er.
x
Low
AC line v
o
ltag
e to
air
hander b
low
er.
x
High
ambien
t
temp
erature
s.
x
Check pow
er to
air
handler
blow
er. Ve
rify
line
v
o
ltage to
blow
er is w
ithin
the
range
spe
cifie
d
on
the air handler
blow
er rating
pla
te.
x
See "In
s
talla
tion In
str
uction
s"
for installa
tion
requi
rements.
x
Turn pow
er OFF pri
or to
repair.
x
Air hand
ler
blow
er fails to
opera
te
.
x
Inte
grated con
trol
module
LED
displa
y
prov
ides
indi
cated error code
.
x
ComfortNe
t™
ther
mosta
t “Call for
Serv
ice” icon il
lumi
nated
.
x
ComfortNe
t™
ther
mosta
t
scroll
s
“Check Air
Handle
r”
message
.
b7
x
Circula
tor
blow
er
motor d
oes no
t
have
enough in
forma
tion
to
operate
prop
erly
.
M
o
tor
fail
s
to
s
tar
t
40
c
o
ns
e
c
ut
iv
e
t
im
e
s
.
MO
T
O
R
PARAM
S
b7
x
Error w
ith
integ
rate
d co
ntro
l
module.
x
Mot
or has a lock
ed
rot
or
condi
tion
.
x
Check in
tegra
ted
control
module. Ve
rify
con
trol
is
populated
w
ith corr
ect shared
data
se
t.
See
da
ta
errors
abov
e for de
tail
s.
x
Chec
k for lock
ed rot
or
condi
tion
(see e
rror
cod
e
abov
e for de
tail
s)
.
x
Turn pow
er OFF pri
or to
repair.
x
Replace
w
ith co
rre
ct
replacemen
t par
t(s)
.
x
Use memory
card
for
the spe
ci
fic
model
.
x
Inse
rt memory
card
BEFORE turning
p
o
w
e
r
ON.
x
Memory
c
a
rd may
be
remov
ed after
da
ta
is
loaded
x
Turn pow
er off
befo
re
remov
ing memor
y
c
a
rd
.
x
Air hand
ler
blow
er operate
s at redu
ce
d
performan
ce
or
ope
rate
s on
low
stage
w
hen high stage
i
s
ex
pected.
x
Inte
grated con
trol
module
LED
displa
y
prov
ides
indi
cated error code
.
b9
x
Airflow
is low
er th
a
n
demanded.
LO
W
ID
AIRFLO
W
b9
x
Blocked
fil
ter
s.
x
Restri
ctiv
e
ductw
ork.
x
Undersi
zed
ductw
ork.
x
Check filte
rs fo
r bl
o
cka
ge.
Clean fi
lter
s or
rem
ov
e
obstruction
.
x
Check du
ctw
ork fo
r blo
ckag
e.
R
e
m
o
v
e
obs
tru
ctio
n.
Veri
fy
all regi
ster
s ar
e
full
y
open.
x
Verify
duc
tw
ork i
s
appropria
tely
si
zed
for
sy
stem
. R
e
si
ze/r
e
p
lace
ductw
ork if ne
ce
ssary
.
x
Turn pow
er OFF pri
or to
repair.
