7500-S
ERIES
I
NSTALLATION
, O
PERATION
AND
S
ERVICE
M
ANUAL
132 of 143
Gas Operation (continued)
19.5 Oil Operation
PROBLEM
POSSIBLE CAUSE
SOLUTION
Car
b
on Monoxide
Readings on Gas Firing
Flame impingement on cold start-
u
p of heat
exchanger ca
u
sed
b
y excessi
v
e firing rate.
Red
u
ce firing rate to correct inp
u
t
v
ol
u
me.
Incorrect gas/air ratios.
Readj
u
st
bu
rner to correct CO
2
/O
2
le
v
els, red
u
cing CO formation to
appropriate le
v
el.
Gas High Fire Inp
u
t
Cannot Be Achie
v
ed
Gas company press
u
re reg
u
lator or meter operat-
ing incorrectly, not allo
w
ing req
u
ired gas press
u
re
at gas train inlet.
Ha
v
e gas company correct.
Gas cock
u
pstream of train inlet not f
u
lly open.
Check and correct.
Gas line o
b
str
u
cted. Check
and
correct.
Gas train main and/or leak test cocks not f
u
lly
open.
Check and correct.
A
u
tomatic gas
v
al
v
e not opening f
u
lly d
u
e to
defecti
v
e operation.
Replace gas
v
al
v
e.
On mod
u
lating
bu
rner,
bu
tterfly
v
al
v
e not f
u
lly
opened.
Readj
u
st.
Defecti
v
e main gas press
u
re reg
u
lator. Replace.
Main gas press
u
re reg
u
lator
v
ent line o
b
str
u
cted. Check
and
correct.
Normally open
v
ent
v
al
v
e (if s
u
pplied) not closing
w
hen a
u
tomatic gas
v
al
v
es open.
Check to see if
v
al
v
e is f
u
lly closed
w
hen a
u
tomatic
v
al
v
es are open.
Replace
v
ent
v
al
v
e, if not closing
f
u
lly.
PROBLEM
POSSIBLE CAUSE
SOLUTION
B
u
rner Motor R
u
ns,
bu
t
Direct Spark Ignited Oil
Flame is Not Esta
b
lished
Defecti
v
e oil nozzle.
Remo
v
e and clean or replace.
Lo
w
oil press
u
re.
Check
w
ith ga
u
ge for correct light-off
press
u
re.
Defecti
v
e oil p
u
mp.
Replace.
Defecti
v
e oil solenoid
v
al
v
e. Replace.
Oil p
u
mp co
u
pling loose or defecti
v
e.
Replace or tighten as req
u
ired.
Lo
w
oil press
u
re s
w
itch (if s
u
pplied) defecti
v
e. Adj
u
st or replace s
w
itch.
Ignition transformer defecti
v
e. Replace.
Ignition electrode set incorrectly.
Remo
v
e electrodes and reset.
Ignition electrodes cracked and gro
u
nding o
u
t
spark.
Replace electrodes.
Ignition lead
w
ire defecti
v
e and gro
u
nding spark
o
u
t.
Replace.
Ignition pl
u
g-in connections at transformer or elec-
trodes loose.
Tighten.
Air flo
w
s
w
itch (if pro
v
ided) not making.
Reset press
u
re or replace.
Defecti
v
e flame safeg
u
ard control or pl
u
g in p
u
rge
timer card.
Replace.
Air dampers held in high fire position d
u
e to
mechanical
b
inding of linkage.
Readj
u
st linkage.
Loose
w
iring connections.
Check and tighten all connections.