27
Part Number 550-142-320/0720
GWA
Series 3
Gas-Fired Water Boilers –
Boiler Manual
Propane Gas Lockout manual reset –
ONLY
after boiler
area has been cleared of any accumulated LP gas:
• Push and hold
TEST
button.
• While holding
TEST
button, rotate
Economy Adjust
knob fully clockwise then fully counter clockwise.
• Release TEST button.
• Control module is
reset.
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.
Figure 21
Ignition control module sequence of operation – status light indications
c. In the event the limit control shuts down the boiler
— The control module closes the main gas valve,
but keeps the circulator 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 position. Cir-
culator is shut off.
6. Boiler is now in the standby mode.
7. Thermostat anticipator setting: Set thermostat heat
anticipator as instructed in
Figure 22, page 28.
10 Sequence of operation – spark-ignited pilot boilers
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 flame 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 satisfied
•
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
10
, Items 3b for control response to failure to proven pilot flame.
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
