L.B. White 220 Therma Grow - Manual (Page 22)

2 21
T
w
o
T
im
e
s
Flash patt
ern
begins 12 seconds af
te
r
condition occur
s.
(Patt
ern
indicat
es
lac
k of air
pr
o
ving in fan
section of unit.)
Are air
-pr
o
ving switch
contacts stuck open?
(P
er
fo
rm continuity check
.)
Does
fan mo
tor star
t up
fo
r prepurge
during initial call
fo
r heat?
Is f
an wheel
binding?
Is f
an wheel
loose on mo
to
r
shaf
t?
Ye
s
Ye
s
Ye
s
No
Check f
o
r binding of
air
-pr
o
ving switch arm
on housing, R
epair or
replace as necessar
y.
Ye
s
Ye
s
Check f
o
r pr
oper clearance of
fan wheel t
o
mo
tor mount. If
good, replace f
an wheel, or
check f
o
r 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.
Ye
s
R
emo
v
e
obstruction.
Clean as necessar
y.
No
Is f
an wheel
plugged with
dir
t?
Is there an obstruction
in blo
w
er outlet pre
v
enting
air
-pr
o
ving switch closure?
No
Are 1
1
5 v
olts sent
fr
om ignition
contr
ol t
erminal
IND t
o
mo
to
r rela
y
No
If im
pr
oper v
o
ltage is supplied,
contact electrician.
- OR -
If no v
oltage is supplied t
o
mo
to
r
rela
y , check wiring be
wtw
een
mo
to
r rela
y and ignition contr
ol. If
good, replace contr
ol.
No
Ye
s
Are 2
4
v
o
lts supplied
fr
om t
erminal PS1
on contr
oller t
o
the
air pr
o
v
ing switch?
Check wiring betw
een module and
com
ponent. R
e
pair or replace as
necessar
y.
If wiring is good, replace
ignition contr
ol module. No
Is
v
o
ltage sent fr
om
rela
y t
o
mo
tor?
Check wiring betw
een
rela
y and mo
to
r.
If
def
ectiv
e, repair as
needed. If good,
replace rela
y
No
Ye
s
Def
ectiv
e mo
to
r.
R
e
place mo
to
r.
Ye
s
Are 2
4
v
o
lts returned
fr
om air pr
o
ving
switch t
o
t
e
rminal
PSO on contr
oller?
No
Def
ectiv
e ignition
contr
ol. R
eplace
ignition contr
ol.
No No
Def
ectiv
e air pr
o
v
ing switch. R
eplace switch.