Weil-McLain CGA Series 2 Manual page 56

CGa Series 2 Gas-Fired Water Boiler — Boiler Manual
11b
Troubleshooting — spark-pilot boilers
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
Are all red lights off?
No Yes
• Wait 30 seconds.
Are all red lights off?
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.
• If you have less than sufficient heat –
Is vent or combustion air piping free of blockage?
No
• Correct conditions and
recheck operation.
• See Figure 24, page 35
for normal sequence of
operation.
56
Yes
• Boiler is in standby.
• Set thermostat to call for
heat and recheck operation.
• Verify Sequence of
operation, Figure 24,
page 35.
Yes
Contact your Weil-McLain
sales representative.
• Replace temperature
• Retest.
• 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.
Is boiler System circulator operating?
No
• 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
• Replace control
module.
• Retest.
• Wait 5 minutes.
Yes
No
• Check temperature
sensor for correct
resistance.
Are resistance values
correct?
No
sensor.
(continued)
Yes
Yes
• Repair/replace
circulator. Retest.
• Repair/replace
wiring. Retest.
Is FLAME light on?
No
Is LIMIT light on?
Yes
• Replace control module.
• Retest.
Yes
Check spill switch and
rollout switch continuity –
are switches closed?
No
• Check any other
limit controls wired
into the limit
circuit. If all are
OK, then replace
control module.
• Retest.
Part Number 550-142-900/0519
Yes