Weil-McLain Gold CGa - Manual (Page 37)

Part Number 550-101-009/0107
3
GOLD CGa Gas-Fired Water Boiler — Boiler Manual
Figure 24 Ignition control module sequence of operation — status light indications
Operation — spark-ignited pilot boilers
9a
Follow all procedures given in this manual and operating
instructions when operating the boiler. Failure to do so
could result in severe personal injury, death or substantial
property damage.
1. Standby: With no call for heat, the vent damper and circulator are de-energized.
No gas flows to pilot or main gas valve.
. Call for heat (thermostat circuit closes):
a. Vent damper and circulator energized if pilot status acceptable. Vent
damper drives open. When vent damper end switch makes circuit, igni-
tion control begins pilot ignition attempt.
b. Ignition control checks for false flame signal: If ignition control senses
pilot signal when no pilot gas should be present, control will lockout,
requiring reset procedure as given in Figure 24.
3. Pilot ignition: Control module sparks the pilot and opens pilot valve in main
gas valve.
a. If pilot does light and control module senses flame current, spark
generator is turned off and main valve opens.
b. If pilot does not light within 15 seconds, pilot valve is closed and
spark generator is turned off. Control module waits 5 minutes, then
attempts to ignite pilot again. This cycle will continue indefinitely if
pilot ignition control does not sense pilot flame.
4. Main burner operation:
a. Control module monitors pilot flame
current. If signal is lost, main valve closes,
spark generator activates and sequence
returns to step 4.
b. If power is interrupted, control system
shuts off pilot and main gas valves and
restarts at step 1 when power is restored.
c. In the event the limit control shuts down
the boiler — The control module closes
the main gas valve, but keeps the circula-
tor operating and the vent damper open.
5. Thermostat satisfied (thermostat circuit opens)
— Pilot and main gas valves are closed — Vent
damper is de-energized, and cycles to closed posi-
tion. Circulator is shut off.
. Boiler is now in the standby mode.
. Thermostat anticipator setting: Set thermostat
heat anticipator as instructed in Figure 25b , page
39.