Sequence of Operation
A
bnorma
l
Operation (cont
.
)
3
.
Pre
ssu
re
Sw
itc
h/Bl
o
w
er
T
emperat
u
re Fa
ul
t:
a) Pre
ss
ure
sw
itc
h
clo
s
ed at
s
tart of call for
h
eat -
Th
e ga
s
contro
l w
ait
s
fo
u
r
s
econd
s
t
h
en, proceed
s
to f
l
a
sh
2 times
w
it
h
3
s
econd pa
us
e
. Th
e contro
l w
ait
s
2 min
u
te
s
and t
h
en t
u
rn
s
on b
l
o
w
er for 3
0 s
econd
s. Th
e b
l
o
w
er
t
u
rn
s
off after 3
0 s
econd
s
and t
h
e contro
l w
ait
s
for pre
ssu
re
sw
itc
h
to open
.
Any time t
h
e Pre
ssu
re
sw
itc
h
open
s
,
t
h
e b
l
o
w
er t
u
rn
s
on (or
s
tay
s
on) and t
h
e contro
l
proceed
s
to
w
ait for pre
ssu
re
sw
itc
h
to c
l
o
s
e
.
b)
Pre
ss
ure
sw
itc
h
or blo
w
er temperature
sw
itc
h
failed open -
Th
e ga
s
contro
l
r
u
n
s
t
h
e b
l
o
w
er for 3
0 s
econd
s
w
aiting for t
h
e pre
ssu
re
sw
itc
h
and
/
or b
l
o
w
er temperat
u
re
sw
itc
h
to c
l
o
s
e
. I
f eit
h
er
sw
itc
h
doe
s
not c
l
o
s
e in 3
0
s
econd
s
, t
h
e b
l
o
w
er t
u
rn
s
off and t
h
e contro
l
f
l
a
sh
e
s
3 times
w
it
h
3
s
econd pa
us
e
. Th
e ga
s
contro
l w
ait
s
t
w
o
min
u
te
s
before t
u
rning on t
h
e b
l
o
w
er for anot
h
er 3
0 s
econd
s
to
s
ee t
h
e circ
u
it c
l
o
s
e
. Th
i
s
cyc
l
e repeat
s
a
s l
ong a
s
t
h
ere i
s
a ca
ll
for
h
eat or
u
nti
l
t
h
e circ
u
it c
l
o
s
e
s.
c) Pre
ss
ure
sw
itc
h
or blo
w
er temperature
sw
itc
h
open
s
during burner operation -
Th
e ga
s
contro
l
t
u
rn
s
off t
h
e
pi
l
ot and main va
l
ve, r
u
n
s
b
l
o
w
er for 1
5 s
econd
s
(inter
-
p
u
rge)
w
aiting for pre
ssu
re
sw
itc
h
and
/
or b
l
o
w
er
temperat
u
re
sw
itc
h
to c
l
o
s
e
. I
f eit
h
er
sw
itc
h
fai
ls
to c
l
o
s
e, t
h
e contro
l
proceed
s
a
s
de
s
cribed in 3b above
. I
f t
h
e
circ
u
it c
l
o
s
e
s
again by t
h
e end of t
h
e inter
-
p
u
rge, t
h
e recyc
l
e co
u
nter i
s
incremented, if t
h
e recyc
l
e co
u
nt
h
a
s
not reac
h
ed it
s l
imit (
4
), anot
h
er tria
l
for ignition begin
s. I
f t
h
e recyc
l
e co
u
nt
h
a
s
been reac
h
ed, t
h
e ga
s
contro
l
t
u
rn
s
off t
h
e b
l
o
w
er and f
l
a
sh
e
s
6 times then 2 times
w
it
h
3
s
econd pa
us
e
. Th
e ga
s
contro
l w
ait
s 5
min
u
te
s
before
repeating ignition
s
eq
u
ence
.
4. T
ria
l
For
I
gnition Fa
ul
t:
a) Pre
ss
ure
sw
itc
h
open
s
during trial -
Th
e ga
s
contro
l
t
u
rn
s
off igniter and pi
l
ot va
l
ve
. Th
e ga
s
contro
l
proceed
s
a
s
de
s
cribed in 3b above
. I
f t
h
e pre
ssu
re
sw
itc
h
c
l
o
s
e
s w
it
h
in 3
0 s
econd
s
t
h
e ga
s
contro
l w
i
ll
contin
u
e
w
it
h
tria
l
for
ignition
s
tarting at b
l
o
w
er pre
-
p
u
rge
.
b) Flame Not Sen
s
ed -
Th
e ga
s
contro
l
energi
z
e
s
t
h
e
s
par
k
igniter attempting to
l
ig
h
t t
h
e pi
l
ot and prove f
l
ame
. I
f
f
l
ame i
s
not
s
en
s
ed
w
it
h
in 9
0 s
econd
s
, t
h
e igniter t
u
rn
s
off, t
h
e pi
l
ot va
l
ve i
s
c
l
o
s
ed and t
h
e ga
s
contro
l
r
u
n
s
t
h
e
b
l
o
w
er t
h
ro
u
g
h
po
s
t p
u
rge and f
l
a
sh
e
s
6 times then once
w
it
h
3
s
econd pa
us
e
. Th
e contro
l w
ait
s 5
min
u
te
s
before
repeating t
h
e ignition
s
eq
u
ence
.
5.
F
l
ame
S
en
s
ing Fa
ul
t:
b) Flame lo
s
t during run -
Th
e ga
s
contro
l
t
u
rn
s
off pi
l
ot and main va
l
ve
s
, r
u
n
s
b
l
o
w
er for 1
5 s
econd
s
(inter p
u
rge)
.
Th
e ga
s
contro
l
increment
s
t
h
e recyc
l
e co
u
nt, if t
h
e recyc
l
e co
u
nt
h
a
s
not reac
h
ed it
s l
imit (
4
), anot
h
er tria
l
for
ignition begin
s. I
f t
h
e recyc
l
e co
u
nt
h
a
s
been reac
h
ed, t
h
e ga
s
contro
l
t
u
rn
s
off t
h
e b
l
o
w
er and f
l
a
sh
e
s
6 times
then 3 times
w
it
h
3
s
econd pa
us
e
. Th
e ga
s
contro
l w
ait
s 5
min
u
te
s
before repeating t
h
e ignition
s
eq
u
ence
.
c) Flame
s
en
s
ed out of
s
equence -
t
h
e ga
s
contro
l
on
l
y
l
oo
ks
for pi
l
ot f
l
ame
wh
en t
h
e b
l
o
w
er i
s
r
u
nning
. I
f f
l
ame i
s
pre
s
ent
wh
en t
h
e pi
l
ot va
l
ve i
s
not open, t
h
e ga
s
contro
l
proceed
s
to
w
ait for f
l
ame
l
o
ss
and f
l
a
sh
e
s
5 times
w
it
h
3
s
econd pa
us
e
. Th
i
s
contin
u
e
s u
nti
l
f
l
ame i
s l
o
s
t, once t
h
e f
l
ame
s
igna
l
i
s l
o
s
t, t
h
e contro
l
f
l
a
sh
e
s
6 times then 4
times
w
it
h
3
s
econd pa
us
e
. Th
e contro
l w
ait
s 5
min
u
te
s
before repeating t
h
e ignition
s
eq
u
ence
.
P
a
g
e
11
11
