SERVICE AND TECHNICAL SUPPORT MANUAL
Gas Furnace: (F/G)9MXE
Specifications subject to change without notice.
440 04 4311 08
25
Figure 16 (Cont.)
Troubleshooting Guide
−
Flow Chart
1 + 2
BL
O
W
ER ON AF
T
E
R PO
W
E
R UP
–
(11
5V
OR
24V
)
–
No
rm
al o
pe
rati
on.
Blower
r
u
ns f
or
9
0
se
co
n
ds, if
u
nit is
po
w
e
re
d u
p
duri
ng
a c
all
f
or
hea
t (R
-
W
/W
1
closed) or whe
n
(R
-W
/W
1 opens
)
du
ri
ng
t
he b
low
er
on
-d
el
a
y pe
riod
.
6 + 1
IGN
IT
ION
LOCK
OUT
–
S
yst
em
fa
iled
to
ign
ite
g
as a
nd
pr
ove
flam
e i
n
4
attem
p
ts. C
on
trol
w
ill
a
uto
-r
eset
af
ter
3
hou
rs.
Ref
er
to s
tat
us c
od
e #
6.
5 ABNOR
M
A
L
F
LA
M
E
-PROV
IN
G
S
IGN
AL
F
lam
e is
p
rov
ed
while
gas
va
lv
e is
de
-
ene
rgi
zed.
Indu
cer
w
ill
r
un
until
fa
ult is
clea
re
d
. C
heck
fo
r:
-
S
tuck
ope
n
or l
eak
y ga
s val
ve.
2
PRESSURE S
W
IT
CH DI
D N
O
T O
PEN
–
Che
ck
fo
r:
- Obst
ruct
ed
pr
ess
ur
e
tu
be.
-
P
re
ssu
re
sw
itch
s
tu
ck c
lo
sed
.
3
LPS o
r HPS PRESSURE S
W
IT
CH DID
NOT
CLOSE
OR REOPENE
D
–
If o
pe
ns
duri
ng blo
wer on
-de
la
y p
e
riod
, b
low
er
w
ill
com
e o
n f
or t
he
se
le
cte
d b
lo
w
e
r
off-
del
a
y.
If LP
S
ope
n lo
ng
er
th
an
5 m
inu
tes,
induc
er
sh
uts
off f
or
15
m
inut
es
bef
or
e
ret
ry
.
If HP
S
ope
n f
or
on
e m
inu
te,
th
en
fur
nac
e
w
ill
lo
ck
out (
aft
er
th
e su
ccessi
ve
trials
) fo
r t
hr
ee
ho
urs
be
for
e r
et
ry
.
Che
ck
fo
r:
- P
rop
er
ve
n
t si
zi
n
g.
-
A
ir leak
b
et
w
e
en
vesti
bul
e a
nd
blo
wer
com
pa
rtm
ent
.
-
Lo
w
in
let
ga
s p
ress
ur
e (if
L
G
P
S
us
ed)
.
-
Discon
nec
te
d
o
r o
bstr
uct
ed
pr
essu
re
tubi
ng.
- Defec
tive
or
m
is
w
ir
ed
pr
es
su
re
sw
itc
hes
-
Ex
ce
ssiv
e w
in
d.
- P
lu
gg
ed
con
de
nsa
te
dr
ain
-
W
ater in
ve
nt pi
pin
g, p
ossi
ble s
ag
gin
g
pi
pe
- Restri
cte
d
ve
nt.
- Defec
tive
In
d
uc
er
m
ot
or
.
-
Lo
w
in
d
uce
r vo
lta
g
e
(11
5 VAC)
4 L
IM
IT
C
IRCU
IT
F
A
ULT
–
In
dica
te
s th
e
lim
it,
flam
e r
oll
o
ut
is
op
en.
B
lo
wer
w
ill
r
un
for
4 m
in.
or
un
til o
pen
s
w
itc
h r
em
ak
es
which
eve
r is l
ong
er
.
If o
p
en
lon
ge
r t
ha
n 3
mi
n,
c
ode
ch
an
ge
s to
lo
ck
ou
t #7
.
If o
p
en
less t
han
3 m
in
. st
atus
co
de
#4
co
nt
inue
s
to fla
sh
until
blo
w
er
sh
uts
off.
Fl
am
e
roll
o
ut s
w
itch
re
qui
res m
a
nu
al r
ese
t.
Che
ck
fo
r:
-
Loo
se blo
wer
whe
el.
-
Defec
tive
sw
itch
o
r co
nn
ectio
ns.
-
Dirt
y filt
er
o
r r
e
str
ic
te
d d
uct s
yste
m
.
-
Im
p
ro
per
g
as in
put
a
djustm
e
nt
-
Im
p
ro
per
lim
it s
w
itc
h o
r n
o lim
it g
ask
et.
T
o det
erm
in
e
w
h
et
her
th
e p
ro
blem
is i
n
the
gas
valv
e, i
gnit
er,
or
flam
e
sen
so
r t
he
sy
stem
c
an be op
er
ate
d
in com
p
one
nt
test m
o
de.
T
o c
heck
th
e ig
nite
r,
rem
ov
e
the R
th
erm
os
tat
co
nne
ctio
n fr
om
th
e
cont
rol,
re
set
po
wer
, st
ar
t th
e
co
m
p
on
e
nt
test.
Do
es t
he i
gnit
er
glo
w
o
ran
ge
/w
hit
e
b
y th
e
end
of
th
e 1
5 s
eco
nd
warm
-up
peri
od
?
Unplu
g ig
nit
er
har
ne
ss f
rom
co
nt
rol
and
rep
eat
com
p
on
ent
te
st
. C
heck
fo
r 1
15
V
bet
wee
n
co
nn
ect
or P
2 (HS
I) a
nd
NE
UT
RA
L-
L
2 o
n t
he c
ont
rol
.
W
as 115
V
pres
en
t fo
r
the 15 sec
on
d
p
eri
od?
Che
ck
co
nn
ectio
ns
and
r
etr
y.
If cu
rr
ent i
s n
ear
t
ypi
cal v
alu
e
(4.
0-
6.
0
μ
A
DC
nom
in
al)
an
d
bur
ne
rs
w
ill
not
sta
y o
n,
repl
ace
co
ntr
ol.
Cl
ean
flam
e
se
nso
r
w
ith
fin
e st
eel
wool
and
r
e
che
ck
cu
rr
en
t. N
om
ina
l cur
re
nt i
s
4.0 to 6.0
μ
A DC.
Is
cu
rre
nt
ne
ar
ty
pic
al
va
lue
?
Rep
la
ce elect
ro
de.
W
ill
m
ain bur
ner
s ig
nite
an
d st
a
y
on
?
Repla
ce f
ur
nac
e c
ont
rol.
Fi
xe
d.
NO
YE
S
YE
S
YE
S
NO
NO
Repla
ce f
ur
nac
e c
ont
rol.
Che
ck
fo
r co
nti
nuit
y i
n t
he
har
nes
s a
nd i
gnit
er.
Re
plac
e
def
ective
com
p
on
ent
.
Reco
nn
ect t
he
R th
erm
os
tat
lea
d
and
s
et
th
e
rm
osta
t to
ca
ll
fo
r h
eat.
Co
nn
ect
voltm
ete
r acr
oss gas valv
e
co
nn
ecti
ons
.
Doe
s
gas
va
lv
e r
ec
eive
24V
?
Does
gas
valv
e
ope
n a
nd
all
o
w g
as t
o
flo
w
?
Do th
e m
ai
n b
ur
ner
s ig
nite
?
Do th
e m
ai
n b
ur
ner
s st
a
y o
n?
A
llo
w blo
wer
to
com
e
on
an
d
rep
eat
tes
t t
o ch
eck
for
interm
itt
en
t o
pe
rati
on.
Check
th
at
gas
valv
e el
ectri
c
sw
itch is
tu
rn
ed on.
Re
plac
e
valve.
Che
ck
co
nn
ectio
ns. I
f OK,
repl
ace
co
ntr
ol.
Che
ck
fo
r:
-
Ina
deq
ua
te fl
am
e c
ar
ry
ov
er
or rou
gh
ig
ni
tion
.
-
Lo
w
in
let
ga
s p
ress
ur
e.
- Pr
op
er
fir
in
g
ra
te
.
Rep
e
at c
all f
or
he
at
and
ch
eck
flam
e
sens
or c
ur
re
nt
duri
ng
trial
fo
r ig
nitio
n
peri
od.
Is
t
he DC
c
urr
en
t b
elo
w
0.5
μ
A
?
YE
S
YE
S
YE
S
YE
S
YE
S
NO
NO
NO
NO
NO
NO
6 IGN
IT
ION
P
R
OV
IN
G
F
A
IL
URE
–
If
fl
a
m
e i
s
not s
en
sed
d
uri
n
g t
he
trial
fo
r ig
nitio
n
peri
od,
th
e c
ont
rol
w
ill
re
pe
at t
he i
gniti
o
n
seq
uen
ce
3 m
or
e tim
es
be
fo
re l
ock
out
#6 +
1 occ
urs
.
If flam
e
sig
nal is
lost
d
u
rin
g t
he
blo
w
e
r on-
del
a
y p
eri
od,
blo
wer
w
ill
c
om
e o
n
for t
he
sel
ecte
d
blo
wer
off
-del
a
y.
C
h
eck
th
e fo
llo
w
ing
be
for
e
goin
g
to
t
he
ne
xt st
ep.
- Gas
va
lve
tu
rn
ed
off
.
-
Man
ual
sh
ut-
off v
alve
o
pen
?
-
Gre
en/
Y
ell
o
w
w
ire
M
U
S
T
be
co
n
nect
ed
to
f
ur
n
ace
sh
eet
m
eta
l.
-
Flam
e s
en
sor
m
ust
not
be
gr
ou
nd
ed.
10
P
O
LA
R
IT
Y
–
Che
ck
for c
or
rec
t lin
e
volta
ge
pol
arit
y.
If u
nits
are
t
w
in
ne
d,
check
fo
r p
ro
pe
r lo
w
-volt
ag
e (
24V
)
tra
nsfo
rm
er ph
asin
g.
7 L
IM
IT
C
IRCU
IT
LOCKOUT
–
L
ock
out
occu
rs if
th
e lim
it, flam
e
r
oll
ou
t is
ope
n
lon
g
er th
a
n 3
m
inu
te
s.
Co
ntr
ol w
ill aut
o-
re
se
t a
fte
r 3
ho
ur
s.
R
efe
r t
o st
atu
s co
d
e
#4.
8 GAS
HEAT
IN
G
L
O
CKOUT
–
Co
ntr
ol
w
ill
N
O
T a
uto
r
es
et. T
u
rn
off
p
o
w
e
r a
nd
wait
5 m
inut
es t
o r
etr
y.
C
heck
f
or:
-
Stu
ck
close
d g
as v
alve
r
el
a
y
on
con
tr
ol.
-
Mis
w
ir
e o
r s
hor
t t
o g
as v
alve
w
ire
.
YE
S
