Crown Boiler BSI172 - Manual (Page 36)

36
Troubleshooting Chart for BSI Boilers Equipped with
Hydrolevel CG400A Low Water Cut-offs and Vent Dampers
Caution: Read page 34 before attempting to use this chart
35
Is there an audible
click as R8225 relay
pulls in w hen the
thermostat calls for
heat?
Does relay
pull in now ?
Vent
damper
open?
START
Thermostat
calls for heat
24 volts across
blue and yellow
w ires inside
junction box?
120 volts across
black and w hite
transformer
leads?
*Pow er off
*Blow n fuse or
tripped
breaker
*Misw ired or
loose 120 volt
connection
N
Y
* Defective
transformer
See Note #6 on
page 34
N
Y
* Bad connection in
thermostat w iring
* Defective thermostat
* Thermostat misw ired or
misapplied
N
N
24 volts betw een
P2 and 2 on
CG400 LWCO?
* Jumper missing
betw een 1 and P1 on
CG400
* Poor connection
betw een transformer
and terminals 1 & 2 on
CG400
24 volts present
betw een each
pressure limit
connection and
yellow transformer
connection?
* Boiler off on pressure limit
* Defective pressure limit
Is 24 volts
present across
brow n and
yellow leads on
R8225 relay?
Disconnect
thermostat and
temporarily jump
boiler thermostat
connections
together
* Loose
connection
betw een
transformer
and R8225
coil
* Defective
R8225
See Note #7
on page 34
Is yellow
LED lit on
LWCO?
* Boiler off on low w ater
* Loose probe connection
* Poor ground path from
heat exchanger to CG400
case
24 volts present
across blue lead on
R8225 and yellow
transformer leads?
* Defective R8225
Y
Y
N
N
Y
Y
Y
N
N
N
Y
Y
Y
N