Weil-McLain CGi 4 Series Manual page 55

CGi
SERIES 4 — GAS-FIRED WATER BOILER —
11c
Troubleshooting — control module lights
–– Usually indicates pressure switch stuck closed or failed to make within 5 minutes ––
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.
• Reset boiler control by turning off power at service switch or turning down thermostat for at least 45 seconds.
• Thermostat should call for heat and appropriate zone valves open.
• Wait 45 seconds.
Does Inducer motor operate?
No
• Remove INDUCER plug (Figure 38, Item 6, page 52) from
plug receptacle of control module.
• Place voltmeter leads across the 120 VAC N and 120 VAC H
pins of the INDUCER receptacle (middle and bottom pins).
Does the voltmeter indicate 120 VAC?
No
• Remove one of the wires connected to the pressure
switch.
• Check continuity across the switch terminals.
Does the ohmmeter indicate the switch is closed?
No
• Replace control module.
• Retest.
Part Number 550-142-302/0124
Boiler Manual
CHART 3 –– PURGE & POWER light flashing
Does inducer motor operate?
No
Yes
Yes
• Try reseating plug in
module receptacle and
restart.
• If inducer still does not
work, replace inducer
assembly.
• Retest.
Yes
• Check air pressure switch
per manual Section 11b.
• Replace if necessary.
• Retest.
Yes
• Wait 5 minutes.
Is PURGE light flashing?
No
• Boiler should be in
normal operating
sequence.
• Observe operation until
thermostat is satisfied
and inducer has
completed its post-purge
cycle.
• Clear passages and recycle boiler.
• Recheck boiler operation.
(cont.)
120
Yes
Are vent or combustion air
passages blocked?
No Yes
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