Weil-McLain CGi 4 Series Manual page 38

CGi
SERIES 4 — GAS-FIRED WATER BOILER —
9a
Operation — sequence
— The circulator continues to operate.
7.
Lower
closed — Inducer operates for 15-second postpurge — Circulator is shut off.
8. Boiler is now in the
9.
Repeat
10.
Return
11. Set thermostat heat anticipator setting as instructed in
Figure 30 &RQWURO PRGXOH VHTXHQFH RI RSHUDWLRQ ² VWDWXV OLJKW LQGLFDWLRQV
STEPS
IROORZLQJ VWHS  F\FOH JRHV EDFN WR VWHS 
1. Standby
• Waiting for call for heat
2. Call for heat
• Circulator on
3. Limit circuit
• Limit controls closed
• Rollout TFE contacts closed
4. Inducer
• Inducer turns on
5. Pressure circuit
• Pressure switch contacts closed
• Prepurge for 10 seconds
6. Flame proven *
• Gas valve open
• Ignitor remains on
• Boiler producing heat
7. Limit cycle
• Limit circuit open
• Gas valve closed
8. Flame outage *
• Flame out
• Boiler recycles
9. Thermostat satisfied
• Circulator off
10. Circulator exercise routine
• Circulator turns on for 30
boiler not operated for 30 days
11. LWCO circuit
• LWCO circuit open
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38
room thermostat setting to stop call for heat. Thermostat is satisfied — Pilot and main gas valves are
.
off cycle
steps through several times to verify operation.
1 6
the thermostat to normal setting.
Call for
POWER TSTAT
Heat?
NO
YES
YES
YES
YES
YES
YES
YES
NO
seconds if NO
YES/NO
Boiler Manual
(continued)
, page 40.
Figure 32
LIMIT PURGE FLAME
CIRC
= ON
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‡  KRXU ZDLWLQJ SHULRG
• 2SHQLQJ DQG FORVLQJ RI WKHUPRVWDW FLUFXLW IRU  WR  VHFRQGV
‡ 5HPRYDO RI  9$& SRZHU IRU  WR  VHFRQGV
Timing
LWCO
= OFF
Part Number 550-142-302/0520
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—
—
—
35
sec
15
sec
—
—
15
sec
30
sec
—