L.B. White HW120 Plus Therma Grow - Manual (Page 24)

24 T
h
re
e
T
im
e
s
Ignition failure Heat
er
does no
t light
or s
ta
y lit.
Is
LP tank
full and pr
operly
sized and are all gas
supply v
a
lv
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
Are 2
4
v
olts sent
fr
om t
e
rminal G
V
of contr
oller t
o
high limit switch
af
ter ignit
er w
arm
up and f
an mo
to
r
restar
ts?
Ha
v
e
the burner
orif
ice, burner
casting and manif
o
ld
been check
ed f
o
r
block
a
ge?
Ye
s
Ye
s
Is pr
oper
burner manif
o
ld
pressure read at
outlet of gas
va
lv
e
?
Does ignit
e
r
glo
w?
Is flame
sensor clean?
Is ignit
e
r
pr
operly
connect
ed?
Are
1
1
5 v
o
lts
supplied fr
om
te
rminal HSI on
ignition contr
ol
module t
o
ignit
er?
Ye
s
Ye
s
Are high limit
switch contacts
closed?
Ye
s
Ye
s
Ye
s
(A)
If lo
w or high pressure
is read, adjust outlet pressure.
(B)
If gas pressure is no
t
read, replace the gas contr
ol v
alv
e.
Def
ectiv
e ignit
e
r.
P
e
rf
orm continuity
check and replace ignit
er If necessar
y.
Clean flame sensor with emer
y clo
th or
st
eel w
o
ol.
Connect ignit
e
r
to
ignit
er po
w
e
r
supply wiring.
Check wiring betw
een module and
com
p
onent. R
epair or replace as
necessar
y or replace ignition contr
ol .
Pr
o
vide pr
oper
pressure t
o
heat
er
and check with a
gauge.
Check f
or v
oltage t
o
switch. Check wiring
and repair if def
ectiv
e
If wiring is good and
v
o
ltage is no
t present,
replace ignition
contr
ol.
No
R
e
mo
v
e
orif
ice and
burner casting. Blo
w
out with com
pressed
air or clean with a
sof
t brush.
No
No
No
No
No
No
No
No
Has wiring been
check
ed
betw
een ignition
contr
ol and
sensor?
Ye
s
Check wiring betw
een
module and
com
ponent. R
epair
or replace .
No
Is
flame sensor
insulat
or
crack
ed?
Ye
s
R
eplace
sensor
.
No
Is
flame sensor
pr
operly
positioned?
Ye
s
P
osition flame
sensor so 1/2 -
3/4 in. of tip is in
burner flame.
No
Is heat
er
pr
operly
gr
ounded?
Contact electrician.
Syst
em must be
gr
ounded f
o
r
pr
oper operation.
No
Are 2
4
v
olts
supplied fr
om
the high limit
switch t
o
the gas
contr
ol v
alv
e?
Ye
s
Check f
or v
oltage t
o
v
alv
e. Check wiring
and repair if def
ectiv
e.
If wiring is good and
v
o
ltage is no
t present,
replace limit switch.
No
P
e
rf
orm continuity check
.
If switch is open reset the switch. Check the f
o
llo
wing:
-- Conf
irm correct fuel f
o
r heat
er
.
-- Pr
oper v
oltage t
o
mo
to
r
-- Dust and dir
t build-up
-- Plugged f
an assembly
-- F
an no
t tight
ened t
o
mo
tor
--
Obstructions in air inlets or
discharge outlet of heat
er
.
Ye
s