Crown Boiler BSI172 Installation Instructions Manual page 39

Main
Y
burners
light?
N
24 volts across
red damper lead
and yellow
transformer
lead?
Y
24 volts across
standing pilot gas
valve terminals or
terminals 5&6 on
S8600 module?
N
24 volts across 1&4
(blue&yellow) and 2&4
(orange&yellow ) on
damper end of
harness?
N
* Defective or
loose damper
harness
Do burners
shut down when
pressure
exceeds limit
setting?
N
* Defective damper
N
* Defective or loose
damper harness
* Obstruction in
path of damper
blade
* Refer to standing pilot
or intermittent ignition
Y
troubleshooting chart
(page 39 or 40).
Y
* Defective or loose
damper harness
* Defective damper
motor
*Obstruction in path
of damper blade
39
38
Do burners shut
Y
down when water
level drops below
cut-off point?
N
* Defective
pressure limit
control
* Blockage in
siphon tube
*LWCO float bowl filled with
mud
* Defective LWCO
DO NOT OPERATE BOILER
UNTIL THIS PROBLEM IS
CORRECTED
24 volts
Y
across spill
switch?
N
24 volts
across rollout
switch?
Y
N
*Loose electrical
connection in spill
switch or rollout
switch wiring or gas
valve common
Y
END
*Chimney blockage
*Chimney system not
contructed in accordance
with Parts 7 and 10 of
National Fuel Gas Code .
*Down draft
*Inadequate combustion air
supply in boiler room
*Rollout switch open.
Replace with exact
replacement (see parts
list). Check for blocked
heat exchanger.