Weil-McLain CGA 2 Series Installation And Maintenance Manual page 56

CGa Series 2 Gas-Fired Water Boiler - Boiler Manual
11
b
Troubleshooting - spark-pilot boilers
<continued)
CHART 6 - Spark-ignited pilot - Insufficient heat or no heat (POWER light on steady)
IA WARNING l
Electrical shock hazard - Wherever you see •
TURN OFF POWER•.
follow the instructions. Failure to follow
instructions could result in severe personal injury, death or substantial property damage.
.
Has it been at least 5 minutes since setting thermostat to
-
Is boiler System circulator operating?
call for heat? If not, wait 5 minutes. Is system heating?
No I Yes
.
Is thermostat set to call for heat? Remove thermostat
wires at boiler and check continuity across the two wires.
•
If
circuit isn't closed, check external thermostat (zone
.
Remove CIRCULATOR harness plug from
valve, relay, etc.) wiring. Correct problems ana retry. CIRCULATOR plug receptacle (Figure 30,
.
Reconnect external thermostat wiring at boiler. Item
7, page 50). Check with voltmeter across
Is thermostat circuit clOsed (continuity across wires)?
pins of control module receptacle.
No Yes
Does voltmeter show 120 VAC across pins?
-
No
I Yes
l
.
Boiler is in standby .
l l
Are all red lights ott?
.
Set thermostat to call for
Replace control
Repair/replace
.
.
No
I
Yes
heat and recheck
module.
circulator. Retest.
•
operation.
.
Retest.
.
Repair/replace .
Verity Sequence of
wiring. Retest.
Wart 30 seconds.
operation. Figure 24,
Are <rll reu
hyl rl~
oil'!
page 35.
No I Yes
t
.
Wart 5 minutes.
•
Is
FLAME
light on?
Replace control module.
I
Yes No
Retest.
L
.
If you have sufficient heat - boiler snould be in normal
Is
LIMIT
light on?
operating sequence. (See normal sequence of operation,
No
Yes
Figure 24,
page 35.)
.
If you have less than sufficient heat -
• •
Is vent or combustion air piping tree of blOckage?
.
Check temperature
.
Replace control module .
No
I I
Yes
sensor for correct
.
Retest.
• •
resistance .
.
Correct conditions and
I
Contact your Weii-Mclain
Are resistance values
recheck operation.
sales representative. correct? .
See
Figure 24,
page 35
No
II
Yes
Check spill switch and
for normal sequence of
+
I
rollout switch continuity -
operation.
are switches closed?
.
Replace temperature
sensor.
No II Yes
.
Retest.
.
Reset spill swrtch, or replace rollout swrtch.
.
Check any other
limit controls wired
E,!·m~IDiil
into the limit
If rollout thermal fuse element or spill swrtch has
circuit. If all are
opened, determine cause and correct condition.
OK, then replace
Failure to do so will cause severe personal injury,
control module.
death or substantial property damage.
.
Retest.
56
Part Number 550-142-779/0712