22
Pr
ob
le
m
22
In
ne
r
C
om
bu
st
io
n
C
on
e L
Li
gh
ts
,
bu
t ww
ill
nn
ot
S
ta
y L
Li
t
Did y
ou
Allo
w Suf
ficient Time
for the Thermocouple
to
W
arm Up?
Is
the Gas Hose
Par
tially
Plugged?
Allo
w 30 - 60
Seconds W
arm-Up
Bef
ore R
eleasing
Pilo
t Butt
on.
R
emo
ve
the Com
ponent and
Clean It.
Ye
s
No
Ye
s
Ye
s
Ye
s
Is
Thermocouple
W
eak or
Def
ectiv
e?
A.
Check Thermofuse in Thermocouple f
or
Continuity
. If Thermofuse is “Open”,
R
eplace Thermocouple.
B.
If Thermofuse is Good, Check Milliv
olt
Output of Thermocouple with Milliv
olt
Test Kit. Output Should be at Least 4 m
v D.C. A R
eading of Less Than 4 m
v
D.C. Can Cause Inner Cone t
o Go Out.
If Thermocouple is W
eak, R
eplace it.
Is Saf
ety
Contr
ol V
alv
e
Def
ectiv
e?
Is Primar
y Orif
ice
Plugged?
R
emo
ve
Orif
ice and Clean It.
Check Gas Pressure t
o the
Heat
er Inlet with a Gas Gauge.
Pr
oper Pressure at High Heat
Should R
ead 5 PSIG. Lo
w Heat
is 1
0
in. W
.C.
No
No
No
Is Thermo-
couple Contact N
ut
Tight
ened Securely int
o
Gas Contr
ol
Valv
e?
Snug Contact N
ut in
Place. (Do No
t
Ov
er
tight
en.) Check f
or
Debris Betw
een Contact
of Thermocouple and Electr
omagnet of V
alv
e.
Ye
s
No
Is
Thermocouple Tip Positioned Pr
operly
int
o Flame?
Position Edge of
Thermocouple t
o be
1/2 - 9/1
6 in. abo
ve
Heat
er’s Housing.
Ye
s
No
Is Butt
on
on Saf
ety Contr
ol
Valv
e F
ully
Depressed?
Depress the Butt
on on the
Pilo
t Saf
ety V
alv
e until Gas
Flo
ws Thr
ough.
Ye
s
No
Check Dr
op-Out of Electr
omagnet in Saf
ety
Contr
ol V
alv
e with the Milliv
olt T
est Kit. The
Valv
e Magnet Should Dr
op Out at 2.0 m
v D.C.
If the Magnet Dr
ops Out abo
ve
2.0 m
v D.C.,
R
eplace the Saf
ety Contr
ol V
alv
e.
Ye
s
Is Pr
oper Gas
Pressure Supplied t
o
the Heat
er?
No