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Part number 550-110-260/0200
31
Boiler Manual
Operation — sequence9a
Figure 18 Control module sequence of operation — status light indications
1.
Read Lighting instructions on page 34. 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. Inducer and circulator energize. After pressure
switch proves proper airflow, control module
initiates 30-second prepurge.
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
flame current, spark generator is turned off and
main valve opens.
5. During
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.
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 satisfied — 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.
1. Standby
Waiting for call for heat·
2. Call for heat
· Circulator on
· Blower on
3. Limit circuit
· Limit controls closed
· Block switch contacts closed
4. Pressure circuit
· Pressure switch contacts closed
· Prepurge for 30 seconds
5. Pilot flame proven *
· Gas valve open
· Pilot remains on
· Boiler producing heat
6. Limit cycle
· Limit circuit open
· Gas valve closed
7. Flame outage *
· Flame out
· Boiler recycles
8. Thermostat satisfied
· Circulator off
· Blower postpurge
9. Circulator exercise routine
· Circulator turns on for 30 seconds
if boiler not operated for 30 days
* If pilot flame is not proven in 15 seconds,control module will flash the FLAME light, but will continue indefinitely with attempts to light the pilot burner.
The control module will not lockout on a failure to establish flame. It will lockout if line voltage polarity is reversed,stray voltage is sensed on thermostat
line, pressure switch sticks closed or fails to make within 5 minutes or if flame is sensed when it shouldn’t be there.The boiler will reset after these lockouts
if any of the following occurs:
• 1 hour waiting period • Opening and closing of thermostat circuit • Removal of 120 VAC power for at least 45 seconds.
POWER TSTAT
CIRC
LIMIT
PRESS
SWITCH
FLAME
Call for
heat?
Timing
or
= "ON"
= "OFF"
NO
NO
NO
YES
YES
YES
YES
YES
YES
—
—
—
35 sec
15 sec
—
—
15 sec
30 sec
Steps
(Following step 8,cycle goes back to step 1.)
26030