CGi Manual

Part Number 550-142-302/0520
CGi
SERIES 4 — GAS-FIRED WATER BOILER — Boiler Manual
55
Troubleshooting — control module lights (cont.)
11c
CHART 3 –– PURGE & POWER light flashing
–– Usually indicates pressure switch stuck closed or failed to make within 5 minutes –– 120
Electrical shock hazardTURN OFF POWER

• 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.
Does inducer motor operate?
No Yes
• Replace control module.
• Retest.
• Check air pressure switch
per manual Section 11b.
• Replace if necessary.
• Retest.
• Clear passages and recycle boiler.
• Recheck boiler operation.
• Try reseating plug in
module receptacle and
restart.
• If inducer still does not
work, replace inducer
assembly.
• Retest.
• Boiler should be in
normal operating
sequence.
• Observe operation until
thermostat is satisfied
and inducer has
completed its post-purge
cycle.
• 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 Yes
• Remove one of the wires connected to the pressure
switch.
• Check continuity across the switch terminals.

No Yes
• Wait 5 minutes.
Is PURGE
No Yes
• Wait 45 seconds.
Does Inducer motor operate?
No Yes
Are vent or combustion air
passages blocked?
No Yes