AERCO BMK 3.0 LN Natural Gas July 2011 - Manual (Page 69)

TROUBLESHO
OTING
8-11
TABLE 8-1. BOILER TRO
UBLESHOOTING – Contin
ued
FAULT INDICATION
PROBABL
E CAU
SES
CORRECTI
VE ACTI
O
N
(co
ntinue
d)
2.
Air/Fuel Valve unplu
gged.
3.
Loo
se
wirin
g co
nne
ctio
n to the
stepp
er moto
r.
4.
Defe
ctive Ai
r/Fuel V
alve
step
pe
r
motor.
5.
Defe
ctive Power Su
pply Board o
r
fus
e
6.
D
efec
tive IGST Board
2.
Che
ck that the Air/Fuel Val
ve is con
ne
cted to the Con
trol Box.
3.
Ins
pec
t for loos
e
co
nnec
tions
b
etwe
en
the Air/Fuel Valve motor
and the wi
rin
g harn
ess.
4.
Repl
ace step
per moto
r.
5.
Che
ck DS1 &
DS2 LEDs o
n Powe
r Sup
ply Board. If they are not
steady O
N
, repla
ce Power Supply Board.
6.
Che
ck “Hea
rtbeat” LE
D DS1 and verify it is blinkin
g ON & OFF
every se
con
d.
If not, replace IGST Board
.
8.2 ADDITI
ONAL
FAULTS
WITHOU
T SPECIFIC F
AULT MESSAGES
Refer to Ta
bl
e 8-2 to trou
bl
esh
oot faults which may
occur with
out a spe
cific faul
t
message be
ing displayed.
TABL
E 8-2. BOILER TROUBLESHOOTIN
G WITH NO FAULT MESSAGE DISPLAYED
OBS
E
RVE
D
INCID
E
N
T
PROBABL
E CAU
SES
CORRECTI
VE ACTI
O
N
Hard Light
-Of
f
1.
Staged Ignitio
n Ball Valve close
d.
2. Clog
ged/da
m
aged
Ignito
r-
Injector
(Figu
re 8
-2).
3.
Defe
ctive Staged Ignition S
olenoi
d
(Figu
re 8
-2)
1.
Open the 1/4
” Ball Valve down
strea
m of the SSOV (Fi
g. 8-1).
2.
Remove a
nd
insp
ect ga
s in
jector
to ens
ure it is
not c
logged or
damag
ed.
3.
Clo
se the 2”
and the 1/4”
Ball Valve down
strea
m
of the SSOV
(Fig. 8-1). Start the unit and lis
ten for a “clic
ki
ng”
so
und that the
Staged Ignitio
n Solenoid m
ake
s du
ring I
gnition Tri
al. If “clicking
”
sou
nd is n
ot heard after 2
or 3 attempts,
r
epla
ce the
Staged
Ignition Solenoid.
Fluctuatin
g G
as Pre
ssure
1.
Gas
pr
es
sure going into un
it is
fluctuating.
2. Dampi
ng
O
rific
e not in
stalle
d.
1.
Stabilize ga
s
pre
ssure goin
g in
to unit. If
necess
ary, troubles
hoot
Building Sup
ply Regul
ator.
2.
C
heck
to ensure that the Damp
ing Orifice is installed in the
SSOV Actuator (Fig
ure 8-3
). For IRI Ga
s Train
s, the Damping
Orifice i
s inst
alled in the d
own
stre
am SSOV Actuator.
Air/Fuel Valve “huntin
g” at
80%
valve position
1.
IGST and Po
wer Su
pply Board
s in
Control Box are outdate
d.
1.
Che
ck to ensure that the IGST and Po
wer Su
pply Board
s a
re
Rev. E or hig
her.