AERCO BMK 3.0 LN Natural Gas July 2011 - Manual (Page 65)

TROUBLESHO
OTING
8
-
7
TABLE 8-1. BOILER TRO
UBLESHOOTING – Contin
ued
FAULT INDICATION
PROBABL
E CAU
SES
CORRECTI
VE ACTI
O
N
HIGH WATE
R
TEMPERATURE
1.
See HIGH WATER TEMPERATURE SWITCH OP
EN.
2.
Temp HI Limit s
etting is
too low
.
1.
See HIGH WATER TEMPERATURE SWITCH OPE
N
.
2.
Check
Temp
HI Limit s
etting.
IGN BOARD
COMM FA
UL
T
1.
Comm
uni
cati
on fault has o
ccurred
betwe
en the
PMC boa
rd a
nd
Ignition/Stepper (IGST) board
1.
Press CLEAR button an
d resta
rt un
it. If
fault pers
is
ts, c
ontac
t
qualified Se
rvice Perso
nnel
.
IG
N SWT
C
H
CLOSE
D
DU
RI
N
G
PU
RGE
1.
Air/Fuel Valve not rotating
2.
Defe
ctive or shorted
swit
ch
3.
Switch wi
re
d inco
rrectly
4.
Defe
ctive Power Su
pply Board o
r
fus
e
5.
D
efec
tive IGST Board
1.
Start the unit. The Air/Fuel
Valve shoul
d rotate to the purg
e
(ope
n) p
ositio
n. If
the valve does n
ot rota
te at all or does not
rotate fully open, che
ck the
Air/Fuel Valve calib
ration.
If
calib
ration i
s okay, the pro
blem may be
in the Air
-Fu
el
Valve or
the Control Box. Refer to q
ualified service person
nel
2.
. If the Air/Fuel Valve does ro
tate to purge, c
heck
the ignition
sw
itc
h for
co
ntinuity between the N.O. and COM terminals
. If the
sw
itc
h show
s c
ontinuity w
hen not in c
ontac
t with the cam
repla
ce the
switch.
3.
Check
to ensure that the sw
itc
h
is
wir
ed
cor
re
ctly (co
rrect
wire
numbe
rs on the normally o
pen termi
nal
s). If the switch is wired
corre
ctly, repl
ace the
swit
ch
4.
Che
ck DS1 &
DS2 LEDs o
n Powe
r Sup
ply Board. If they are not
steady O
N
, repla
ce Power Supply Board.
5.
Che
ck “Hea
rtbeat” LE
D DS1 and verify it is blink
in
g ON & OFF
every s
ec
ond. If
not, replace IGST Board
IGN SWTCH
OPEN
DU
RI
N
G
IG
N
ITI
ON
1.
Air/Fuel Valve not rotating
to ignition
positio
n.
2.
Defe
ctive igni
tion swit
ch
3.
Defe
ctive Power Su
pply Board o
r
fus
e
4.
Defe
ctive IGST Board
1.
Start the unit. The Air/Fuel Va
lve
sh
ould rotate to the purge
(ope
n)
po
sition, then
ba
ck to ig
nition
positio
n (to
w
ard
s
clo
sed
)
during the ignition c
yc
le. If the va
lve does
not rotate
back
to the
ignition po
sit
ion, che
ck the Air/Fuel
Valve cali
bration. If
calib
ration i
s okay, the pro
blem may be
in the Air/Fuel Valve or
the Control Box. Refer faul
t to qualified servi
ce pe
rso
nnel.
2.
If the Air/Fuel Valve does rota
te to the ignition pos
ition, c
heck
the ignition pos
ition switch for
contin
uity betwe
en th
e N.O.
and
COM terminals
w
hen in contac
t w
ith the c
am.
3.
Che
ck DS1 &
DS2 LEDs o
n Powe
r Sup
ply Board. If they are not
steady O
N
, repla
ce Pow
er Supply Board.
4.
Che
ck “Hea
rtbeat” LE
D DS1 and ve
rify it is blinkin
g ON & OFF
every s
ec
ond. If
not, replace IGST Board.