L.B. White AW250(Smart Box controller) - Manual (Page 24)

24
Three Times Ignition failure. The module has gone into safety lockout.
Is
LP tank
full and pr
operly
sized and are all gas
supply v
alv
es t
o
heat
er open?
Fill tank or resize if
necessar
y.
Open all
gas Supply v
alv
es
Ye
s
No
Is pr
oper gas
pressure supplied
to
heat
er?
Ye
s
H
av
e
the burner
orif
ice, burner
casting and manif
old
been check
ed f
o
r
block
age?
Is
burner manif
old
pressure read at
outlet of gas
v
alv
e?
Does ignit
er
glo
w?
Is flame sensor
clean?
Is ignit
er
pr
operly
connect
ed?
Are
1
1
5 v
olts
supplied fr
om
ignition contr
ol
module t
o
ignit
er?
Ye
s
Ye
s
Are high limit
switch contacts
closed?
Ye
s
Ye
s
Ye
s
If contacts are open,
reset the switch.
Det
ermine cause of
high limit tripping.
See f
o
o
tno
te
at the
end of the
tr
oubleshoo
ting
section.
If pressure is no
t read,
check ohm reading betw
een wires of recitif
ier
plug as connect
ed t
o
gas
contr
ol. R
eading should be
3 meg ohm. If reading sho
ws o
v
erload or 0 ohms,
replace the rectif
ier plug
and recy
cle the heat
er
. If
pr
oblem still e
xists, replace
the gas contr
ol v
alv
e.
Def
ectiv
e ignit
er
.
P
e
rf
orm ohm check
and replace ignit
er If
necessar
y.
Clean flame sensor with emer
y clo
th or
st
eel w
ool.
Connect ignit
er
to
ignit
er po
w
e
r
supply wiring.
Check wiring betw
een contr
ol module
and ignit
er
. R
epair or replace as
necessar
y.
If wiring is good, replace
ignition contr
ol module.
Pr
o
vide pr
oper
pressure t
o
heat
er and
check with a gauge.
No
R
emo
v
e
com
ponents
and blo
w out with
com
pressed air or
clean with a sof
t
brush.
No
No
No
No
No
No
No
Is wiring betw
een
flame sensor and ignition contr
ol in
good condition?
Ye
s
Check wiring, repair or
replace as needed.
No
Is
flame sensor
insulat
or
crack
ed?
Ye
s
R
eplace sensor
.
No
Ensure pr
oper
position of flame
sensor
. (1/2 t
o
3/4 of tip in
burner flame)
Ye
s
Is heat
er
pr
operly
gr
ounded?
Contact electrician.
syst
em must be
gr
ounded f
o
r
pr
oper operation.
No
Ye
s
Is high limit
receiving 2
4
v
olts
fr
om ignition
contr
ol?
A
. Check f
or def
ectiv
e
wires, repair or replace. B. If wires are good and v
oltage is no
t deliv
ered,
replace ignition contr
ol.
No
Ye
s
Ye
s