L.B. White 170 Tradesman Portable Forced Air - Manual (Page 23)

F
an runs,
heater does not light.
Open fuel supply
v
a
v
es .
Pr
o
vide pr
oper
gas pressure t
o
heat
er inlet.
Check continuity acr
oss
switch. If contacts are
open det
ermine cause.
Check f
or:
pr
oper v
oltage, block
ages
at air inlets or outlet, loose
fan, or lo
w f
an speed.
If good, replace backflash
switch.
Are all fuel
supply v
alv
es
open?
Is pr
oper
gas pressure
supplied?
Are the
backflash switch contacts closed?
Does gas
solenoid v
a
lv
e open?
Is pr
oper
v
oltage
supplied t
o
v
alv
e?
Def
ectiv
e wires or
connections. If good,
replace ignition contr
ol.
Def
ectiv
e
v
alv
e.
Does ignit
or
spark?
Is high v
oltage
lead securely connect
ed t
o
ignition contr
ol
and ignit
or?
Connect High V
olt
age
Lead
Is ignit
or
pr
operly
gapped?
Check ignit
er gap
R
egap t
o
3/1
6 in.
Is ignit
or gap
positioned
to
w
a
rd
burner
orif
ice?
R
eposition ignit
er
.
(See Ser
vice Instructions)
23
TRADESMAN HEATER
Problem
Ye
s
Ye
s
Ye
s
Ye
s
Ye
s
Ye
s
Ye
s
Ye
s
No
No
No
No
No
No
No
No
Det
ermine if ignit
or receiv
es high v
oltage:
-- Disconnect ignition lead fr
om ignition contr
ol.
-- P
osition a scre
wdriv
er tip about 3/1
6 inch a
w
a
y
fr
om ignition contr
ol where lead w
as connect
ed .
-- WITH GAS OFF
, star
t the heat
er
.
-- If no spark is seen, replace the igntion contr
ol.
-- If spark is seen, reconnect igntion lead t
o
contr
ol.
-- Disconnect the lead at the ignit
or
.
-- Hold the lead about 3/1
6 in. fr
om a gr
ounded
section of the heat
er
.
-- WITH GAS OFF
, star
t the heat
er
.
-- If no spark is obser
v
ed, replace the ignition lead.
-- If spark is obser
v
ed, replace the ignit
or
.
No
Ye
s
Check the burner orif
ice
for block
age. Clean or
replace the orif
ice .