15
TROUBLESHOOTING INFORMATION: AIR HANDLER DIAGNOSTIC CODES
Co
m
fo
r
tNet™
Therm
ost
at On
ly
Sym
ptom
s of A
bnor
m
al Opera
ti
on (Le
g
a
c
y
& Com
fortNet™ Th
erm
ostat
)
D
ia
g
no
st
ic
/St
atus
LED Codes
Fault De
scr
ipt
ion
Messa
ge
Code
P
o
ss
ib
le C
a
u
se
s
Correct
ive Action
s
No
tes
& Ca
utio
ns
x
LED d
isp
la
y
i
s ON co
nti
nuo
us
ly
ON
x
Norm
al opera
tion
N
one N
one
x
Norm
al opera
tion
x
N
one
x
Norm
al opera
tion
x
Electric
hea
ter
s fa
il
to energize
on a ca
ll f
o
r
W
1
or A
u
x
il
iary
/E
m
erge
ncy
heat
x
Int
egr
ate
d c
o
ntr
o
l m
o
du
le L
E
D
di
sp
lay
p
rovi
des
t
h
e in
di
cat
ed
erro
r co
d
e.
x
Com
fortNet™ therm
os
ta
t “
C
all for
Service” ic
on illum
inate
d
x
Com
fortNet™ therm
os
ta
t scr
o
lls “
C
heck
Ai
r Hand
le
r” m
es
sa
ge
1 Fla
sh
x
Heater
kit se
le
cte
d via
d
ips
wi
tches
i
s t
o
o
larg
e
fo
r heat
er kit
s
sp
eci
fied
in sh
are
d
da
ta set
HTR TOO
LARGE
Ec
x
Heater
kit se
le
cte
d via
d
ips
wi
tches
i
s
to
o
larg
e fo
r h
eat
er
k
it
s
in
sh
ared
dat
a
se
t
x
Verify
electr
ic
hea
t dipsw
itc
h
se
tti
ngs
x
Verify
the insta
lled e
lectr
ic
hea
ter
is
val
id
for t
h
e m
odular
bl
ow
er. Ch
ec
k nam
epla
te
or
Sp
eci
fi
cat
ion
Sh
eet
ap
pli
cab
le
to
y
our
m
odel
* f
o
r a
ll
o
w
able
hea
ter
ki
t(
s).
x
Verify
share
d data
se
t is c
o
rrec
t
for the
specific m
ode
l. Re-
po
p
u
la
te
da
ta u
sin
g c
o
rrec
t
m
e
m
o
ry
card if re
quired.
x
T
u
rn
pow
er
O
FF pr
io
r to
repa
ir.
x
Use m
e
m
o
ry
card for
the
spe
cif
ic m
odel.
x
Insert m
e
m
o
ry
card
BEFORE t
u
rn
ing
power
O
N
. Mem
ory
card
m
ay
be
rem
oved af
ter
dat
a i
s
loa
de
d.
x
Electric
hea
t airflow
is higher
than
expec
ted
on a ca
ll f
o
r W
1
or
Au
xi
li
ary
/E
m
erg
ency h
eat
x
Int
egr
ate
d c
o
ntr
o
l m
o
du
le L
E
D
di
sp
lay
p
rovi
des
t
h
e in
di
cat
ed
erro
r co
d
e.
1 Fla
sh
x
Heater
kit se
le
cte
d via
d
ips
wi
tches
i
s t
o
o
s
m
al
l
fo
r heat
er kit
s
sp
eci
fied
in sh
are
d
da
ta set
HTR TOO
SMALL
Ec
x
Heater
kit se
le
cte
d via
d
ips
wi
tches
i
s t
o
o
s
m
al
l
fo
r h
eat
er
k
it
s
in
sh
ared
dat
a
se
t
x
Verify
electr
ic
hea
t dipsw
itc
h
se
tti
ngs
x
Verify
the insta
lled e
lectr
ic
hea
ter
is
val
id
for t
h
e m
odular
bl
ow
er. Ch
ec
k nam
epla
te
or
Sp
eci
fi
cat
ion
Sh
eet
ap
pli
cab
le
to
y
our
m
odel
* f
o
r a
ll
o
w
able
hea
ter
ki
t(
s).
x
Verify
share
d data
se
t is c
o
rrec
t
for the
specific m
ode
l. Re-
po
p
u
la
te
da
ta u
sin
g c
o
rrec
t
m
e
m
o
ry
card if re
quired.
x
T
u
rn
pow
er
O
FF pr
io
r to
repa
ir.
x
Use m
e
m
o
ry
card for
the
spe
cif
ic m
odel.
x
Insert m
e
m
o
ry
card
BEFORE t
u
rn
ing
power
O
N
. Mem
ory
card
m
ay
be
rem
oved af
ter
dat
a i
s
loa
de
d.
x
Electric
hea
t airflow
is higher
than
expec
ted
on a ca
ll f
o
r W
1
or
Au
xi
li
ary
/E
m
erg
ency h
eat
x
Int
egr
ate
d c
o
ntr
o
l m
o
du
le L
E
D
di
sp
lay
p
rovi
des
t
h
e in
di
cat
ed
erro
r co
d
e.
1 Fla
sh
x
Heater
kit se
le
cte
d via
d
ips
wi
tches
d
o
es
n
o
t
hea
ter kits specifie
d in
sh
ar
ed
d
at
a se
t
NO HTR
MATCH
Ec
x
Heater
kit se
le
cte
d via
d
ips
wi
tches
i
s d
o
esn
’t
m
at
ch
hea
ter ki
ts in s
h
are
d dat
a
se
t
x
Verify
electr
ic
hea
t dipsw
itc
h
se
tti
ngs
x
Verify
the insta
lled e
lectr
ic
hea
ter
is
val
id
for t
h
e m
odular
bl
ow
er. Ch
ec
k nam
epla
te
or
Sp
eci
fi
cat
ion
Sh
eet
ap
pli
cab
le
to
y
our
m
odel
* f
o
r a
ll
o
w
able
hea
ter
ki
t(
s).
x
Verify
share
d data
se
t is c
o
rrec
t
for the
specific m
ode
l. Re-
po
p
u
la
te
da
ta u
sin
g c
o
rrec
t
m
e
m
o
ry
card if re
quired.
x
T
u
rn
pow
er
O
FF pr
io
r to
repa
ir.
x
Use m
e
m
o
ry
card for
the
spe
cif
ic m
odel.
x
Insert m
e
m
o
ry
card
BEFORE t
u
rn
ing
power
O
N
. Mem
ory
card
m
ay
be
rem
oved af
ter
dat
a i
s
loa
de
d.
x
N
o
m
odular b
low
er o
p
era
ti
o
n
.
x
Int
egr
ate
d c
o
ntr
o
l m
o
du
le L
E
D
di
sp
lay
p
rovi
des
t
h
e in
di
cat
ed
erro
r co
d
e.
x
Com
fortN
et
™ t
h
erm
os
ta
t d
is
p
lay
s
“B
atter
y
Power”
5 Fla
sh
es
x
Op
en
Fus
e
No
t
Di
sp
la
y
ed
No
t
Disp
la
y
ed
x
Sho
rt in low
vo
lt
ag
e
w
iri
ng
x
Locate
and
co
rre
ct short in low
v
olt
age wi
ri
ng
x
T
u
rn
pow
er
O
FF pr
io
r to
repa
ir.
x
Replace f
u
se with
3-a
m
p
aut
om
oti
ve ty
pe
x
Mo
du
lar bl
ow
er
fa
il
s to op
era
te
x
Int
egr
ate
d c
o
ntr
o
l m
o
du
le L
E
D
di
sp
lay
p
rovi
des
n
o
s
ign
al
.
x
Com
fortNet™ therm
os
ta
t “
C
all for
Service” ic
on illum
inate
d
x
Com
fortNet™ therm
os
ta
t scr
o
lls “
C
heck
Ai
r Hand
le
r” m
es
sa
ge
N
one
x
No
20
8/2
30
vol
t
p
o
w
er
to
m
odu
lar bl
ow
er or no
2
4
vo
lt
po
wer to
in
te
gra
te
d co
n
tro
l
m
odule
x
Blow
n f
u
se
or c
irc
ui
t
brea
ker
x
In
te
g
ra
ted
con
trol
m
odule has
an
in
ter
n
al
fau
lt.
INTERNAL
FAULT
EE
x
Manu
al
di
sconn
ect
swi
tc
h
OFF o
r
24 v
o
lt
w
ire im
proper
ly
co
nne
cte
d or
lo
o
se
x
Blow
n f
u
se
or c
irc
ui
t
brea
ker
x
Int
egr
ate
d c
o
ntr
o
l m
o
du
le
has
an
in
ter
na
l fa
ul
t
x
As
su
re 208
/23
0
vo
lt
and
24
vo
lt
pow
er
to
m
odula
r b
lo
w
er an
d
in
te
gra
te
d co
n
tro
l m
odu
le.
x
Ch
eck
int
eg
rated
cont
rol
m
o
d
u
le
fuse (3A). Re
place if
nece
ssary
.
x
Ch
eck
fo
r pos
si
bl
e
sh
o
rts
in
2
08/
230
vo
lt
an
d
24
v
olt
ci
rcui
ts
.
Repa
ir a
s ne
ces
sary
.
x
Replace
ba
d integr
ate
d control
m
odule.
x
T
u
rn
pow
er
O
FF pr
io
r to
repa
ir.
x
Replace inte
gra
te
d
contr
o
l
m
odule f
u
se
w
it
h
3A
au
to
m
o
ti
v
e f
u
se.
x
Replace inte
gra
te
d
contr
o
l
m
odule w
ith
cor
rec
t
replacem
ent part
x
Read prec
autions in
“E
lectros
tatic Disc
ha
rge”
sec
ti
o
n
of m
anua
l.
Summary of Contents for MBVC
Page 14: ...14 APPENDIX A ...
