Part Number 550-142-300/0520
56
CGa Series 3 Gas-Fired Water Boiler — Boiler Manual
11b
Troubleshooting — spark-pilot boilers
(continued)
CHART 6 –– Spark-ignited pilot ––
Insufficient heat or no heat (
POWER
light on steady)
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
call for heat? If not, wait 5 minutes. Is system heating?
• 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
valve, relay, etc.) wiring. Correct problems and retry.
• Reconnect external thermostat wiring at boiler.
Is thermostat circuit closed (continuity across wires)?
No
Yes
Is boiler System circulator operating?
No
Yes
• Wait 5 minutes.
Is FLAME light on?
Yes
No
Is LIMIT light on?
No
Yes
Are all red lights off?
No
Yes
• Wait 30 seconds.
Are all red lights off?
No
Yes
Check spill switch and
rollout switch continuity –
Are switches closed?
No
Yes
• Reset spill switch, or replace rollout switch.
If rollout thermal fuse element or spill switch has
opened, determine cause and correct condition.
Failure to do so will cause severe personal injury,
death or substantial property damage.
• Check temperature
sensor for correct
resistance.
Are resistance values
correct?
No
Yes
• Replace control
module.
• Retest.
• Replace control
module.
• Retest.
• Repair/replace
circulator. Retest.
• Repair/replace
wiring. Retest.
• Check any other
limit controls wired
into the limit
circuit. If all are
OK, then replace
control module.
• Retest.
• Correct conditions and
recheck operation.
• See
Figure 24,
page 35
for normal sequence of
operation.
• Boiler is in standby.
• Set thermostat to call for
heat and recheck operation.
• Verify
Sequence of
operation, Figure 24,
page 35.
• Remove
CIRCULATOR
harness plug from
CIRCULATOR
plug receptacle (
Figure 30,
Item 7
, page 50). Check with voltmeter across
pins of control module receptacle.
Does voltmeter show 120 VAC across pins?
No
Yes
• Replace control module.
• Retest.
• If you have sufficient heat – boiler should be in normal
operating sequence. (See normal sequence of operation,
Figure 24
, page 35.
• I
f you have less than sufficient heat –
Is vent or combustion air piping free of blockage?
No
Yes
Contact your Weil-McLain
Technical support.
• Replace temperature
sensor.
• Retest.