Weil-McLain 550-110-260/0508 Boiler User Manual


 
Part number 550-110-260/0508
31
GOLD CGs Gas-Fired Water Boiler — Boiler Manual
Operation — sequence9a
Figure 18 Control module sequence of operation — status light indications
1. Read appropriate Operating instructions in
Section 9c. This information is also located on a
label on the inside of the boiler jacket door panel.
2.
Raise room thermostat to call for heat.
3.
Circulator energizes. If limit circuit is closed, the
inducer starts. After pressure switch proves proper
airfl ow, control module initiates a 30-second pre-
purge.
4.
Control module sparks the pilot and opens pilot
valve in main gas valve.
a. If pilot
does not light within 15 seconds, pilot
valve is closed and spark generator is turned
off. Control module initiates a 15-second
postpurge, then starts a new cycle.
b. If pilot
does light and control module senses
ame current, spark generator is turned off
and main valve opens.
5. During
main burner operation:
a. Control module monitors pilot fl ame current.
If signal is lost, main valve closes, spark gen-
erator 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.
6. In the event the limit control shuts down the
boiler
— The control module closes the pilot and
main gas valves, but keeps the inducer operating for
15-second postpurge.
— The circulator continues to operate.
7. Lower room thermostat setting to stop call for
heat. Thermostat is satisfi ed — Pilot and main gas
valves are closed — Inducer operates for 15-second
postpurge — Circulator is shut off.
8. Boiler is now in the off cycle.
9. Repeat steps 1 through 6 several times to verify
operation.
10. Return the thermostat to normal setting.
11. Set thermostat heat anticipator setting to 0.4 amps,
adjusted for gas valve and control current.