Operating instructions

20
Part Number 550-142-784/0812
GWA Series 2 Gas-Fired Water Boilers – Boiler Manual
9 Sequence of operation – spark-ignited pilot boilers
5. Thermostat satisfied (thermostat circuit opens) — Pilot
andmaingasvalvesareclosed—Ventdamperisde-
energized,andcyclestoclosedposition.Circulatoris
shutoff.
6. Boiler is now in the standby mode.
7. Thermostat anticipator setting: Set thermostat heat
anticipator as instructed in Figure 15b, page 22.
Figure 14 Ignition control module sequence of operation – status light indications
Steps
(following step 7, cycle goes back to step 1.)
Call for
heat?
POWER
TSTAT
CIRC
LIMIT DAMPER FLAME
TIMING
1. Standby
• Waiting for call for heat
NO
–––
2. Call for heat
• Circulator on
YES
–––
3. Limit circuit
• Limit controls closed
YES
–––
4. Damper circuit
• Damper proven open
YES
–––
5. Pilotameproven *
• Gas valve open
• Pilot remains on
• Boiler producing heat
YES
15 sec
6. Limit cycle
• Limit circuit open
YES
–––
7. Flame outage
• Flame out
• Boiler recycles
YES
–––
8. Thermostatsatised
• Circulator off
NO
15 sec
9. Circulator exercise routine
• Circulator turns on for 30 seconds if
boiler not operated for 30 days
NO
30 sec
= “ON” = “OFF”
*SeeSection9,Items3bforcontrolresponsetofailuretoprovenpilotame.
Control will lockout under the following conditions:
· Linevoltagepolarityisreversed
· Strayvoltageissensedonthermostatline
· Damperendswitchnotprovenwithin5minutesfromthermostatcallforheat
· Flame is sensed when it shouldn’t be there
Control will reset after these lockouts if any of the following occur
· 1 hour waiting period
· Opening and closing of thermostat circuit for
2 to 20 seconds
59340 GWA