CGi Manual

Part Number 550-142-302/0520
CGi
SERIES 4 — GAS-FIRED WATER BOILER — Boiler Manual
60
Troubleshooting — control module lights (cont.)
11c
CHART 8 –– Insufficient heat or no heat to system (POWER light on steady)
Electrical shock hazardTURN OFF POWER

• 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.
!"
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
• Replace rollout switch.
If rollout thermal fuse element 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 30, page 38
for normal sequence of
operation.
• Boiler is in standby.
• Set thermostat to call for
heat and recheck operation.
• Verify Sequence of
operation, Figure 30,
page 38.
• Remove CIRCULATOR harness plug from
CIRCULATOR plug receptacle (Figure 38, Item
7, page 52). Check with voltmeter across pins of
control module receptacle.
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 30, page 38.
• If you have less than sufficient heat –
Is vent piping free of blockage?
No Yes
• Contact Weil-McLain
Technical support or
replace gas valve.
• Replace temperature
sensor.
• Retest.
• Check heat loss calculation
versus boiler size.
• Clock gas input.
No
Is manifold pressure:
3.50” w.c. on natural gas?
10.0” w.c. on propane?
Yes No
#$
continuity –

No Yes