L.B. White AD250(Spark Ignition) - Manual (Page 23)

Tw
o Times
Flash patt
ern
begins 12 seconds af
te
r
condition occur
s.
(Patt
ern
indicat
es
lac
k of air
pr
oving in fan
section of unit.)
Are
air
-pr
oving switch
contacts stuck open? (P
er
form continuity
check
.)
Does
fan mo
tor star
t up
for prepurge
during initial call
for heat?
Is
fan wheel binding?
Is f
an wheel
loose on mo
to
r
shaf
t?
Ye
s
Ye
s
Ye
s
No
Check f
or binding of
air
-pr
oving switch arm
on housing, air
-pr
oving
flapper stuck, or out of adjustment. R
epair or
replace as necessar
y.
Ye
s
Ye
s
Check f
or pr
oper clearance of
fan wheel t
o mo
tor mount. If
good, replace f
an wheel, or
check f
or housing alignment.
Tight
en set scre
w(s) on f
an.
Mak
e sure set scre
w(s) are
tight
ened against flat(s) of
mo
tor shaf
t.
Ye
s
Clean the f
an wheel with
com
pressed air or sof
t brush.
Def
ectiv
e mo
to
r
or capacit
or
.
R
eplace mo
to
r.
Ye
s
R
emo
ve
obstruction.
Clean as necessar
y.
No
Is f
an wheel
plugged with
dir
t? No
Is there
an obstruction in blo
w
er outlet
pre
venting air
-pr
oving
switch closure?
No
Is
pr
oper v
oltage
supplied t
o mo
to
r
fr
om ignition module?
No
If im
pr
oper v
oltage is supplied,
contact electrician.
- OR -
If no v
oltage is supplied t
o
mo
to
r, check wiring, replace
mo
tor rela
y (if applicable), or
replace ignition contr
ol module.
No
Ye
s
Is
pr
oper
voltage being
sent t
o air
-pr
oving
switch?
Check wiring betw
een
module and com
ponent.
R
epair or replace as
necessar
y,
or replace
ignition contr
ol module.
No
22