Weil-McLain CGi 4 Series Manual page 60

CGi
SERIES 4 — GAS-FIRED WATER BOILER —
11c
Troubleshooting — control module lights
CHART 8 –– Insufficient heat or no heat to system (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 30, page 38.
• If you have less than sufficient heat –
Is vent piping free of blockage?
No
• Correct conditions and
recheck operation.
• See Figure 30, page 38
for normal sequence of
operation.
• Check heat loss calculation
versus boiler size.
• Clock gas input.
60
Boiler Manual
Yes
• Boiler is in standby.
• Set thermostat to call for heat
and recheck operation.
• Verify Sequence of
operation, Figure 30,
page 38.
Yes
Is manifold pressure:
3.50" w.c. on natural gas?
10.0" w.c. on propane?
Yes No
• Contact Weil-McLain
Technical support or
replace gas valve.
No
• Replace temperature
sensor.
• Retest.
Is boiler System circulator operating?
No
• Remove CIRCULATOR harness plug from
CIRCULATOR plug receptacle (Figure 38, Item
7, page 52). Check with voltmeter across pins of
control module receptacle.
Does voltmeter show 120 VAC across pins?
No
• Replace control • Repair/replace
module.
• Retest.
• Repair/replace
• Wait 5 minutes.
Is FLAME light on?
Yes
Is LIMIT light on?
No
• Check temperature
sensor for correct
resistance.
Are resistance values
correct?
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.
Part Number 550-142-302/0124
(cont.)
Yes
Yes
circulator. Retest.
wiring. Retest.
No
Yes
• Replace control module.
• Retest.
Check rollout switch
continuity –
Is switch closed?
No Yes
• Check any other
limit controls wired
into the limit
circuit. If all are
OK, then replace
control module.
• Retest.