L.B. White Pilot User Manual
Page 39
August 1999
5.1-5
5
Pr
ob
lem 3
Motor runs.
Burner
does not
light with
pilot light
lit.
F
or units with air pro
ving
s
witch or centr
ifugal s
witch,
is proper v
oltage being
deliv
ered to the
s
witch?
Ye
s
No
Ye
s
Ye
s
Ye
s
Ye
s
Are air pro
ving
s
witch or centr
ifugal
s
witch contacts opening
and closing proper
ly?
(P
erf
or
m a contin
uity
chec
k.)
Is flapper
(if applicab
le)
binding?
Repair or replace flapper
.
Chec
k v
oltage supply
,
electr
ical connections to
s
witch and wires f
or
contin
uity
.
Repair as
necessar
y.
Replace air pro
ving s
witch
or f
or units with centr
ifugal
s
witch, replace motor
.
Is
flapper ar
m
(if applicab
le)
engaging s
witch
ar
m proper
ly?
Adjust flapper ar
m to
engage s
witch ar
m or clean
out an
y debr
is from around
flapper or air flo
w s
witch.
Tighten set scre
ws
to motor shaft.
Reset s
witch.
Deter
mine cause of
high limit tr
ipping.
(See Prob
lem 7.)
Ye
s
Clean out debr
is
.
Chec
k electr
ical connections
to high limit s
witch and to control v
alv
e
and chec
k wires f
or contin
uity
.
Chec
k f
or proper pressure
using lo
w pressure gas gauge
.
Ref
er to heater nameplate
.
Ye
s
Ye
s
Ha
v
e
y
ou chec
k
ed
for proper inlet and
b
u
rner manif
old pressure
at gas control v
alv
e?
If proper gas pressure is supplied to the
inlet of the gas control v
alv
e
, b
ut b
u
rner
manif
old pressure is not apparent, then
replace the control v
alv
e
.
Is high limit
s
witch
tr
ipped?
No
No
No
Are
b
u
rner
or
ifice
, b
u
rner
casting or manif
old
plugged?
No
No
No
Ye
s
Is
fan tightened
proper
ly to motor
shaft?
No
Is proper v
oltage
supplied to and
from high limit
s
witch to control
v
alv
e?
No