21
Thermostat actuates on call for heat, completing circuit
to control. Completed circuit to control will first activate
circulator. Control will first monitor water temperature
with circulator running to determine if thermostat can be
satisfed without firing burner; if not it will activate damper
which closes end switch inside damper. Action completes
circuit to ignition system and ignition takes place.
In event boiler water temperature exceeds high limit
setting on boiler mounted high limit control, power is
interrupted between control system and ignition system.
Power remains off until boiler water temperature drops
below high limit setting. Circulator continues to operate
under this condition until thermostat is satisfied.
In event flow of combustion products through boiler venting
system becomes blocked, blocked vent safety switch shuts
main burner gas off. Similarly, if boiler flue-way becomes
blocked, flame rollout safety switch shuts main burner
gas off. See Figure 15
.
If either of these conditions occur,
do not attempt to place boiler back into operation.
Contact certified service agency
.
Before seasonal start-up, have certified service agency
check boiler for soot and scale in flues, clean burners and
check gas input rate to maintain high operating efficiency.
WARNING
Label all wires prior to disconnection when servicing
controls. Wiring errors could cause improper and
dangerous operation.
!
Verify proper operation after service.
Service agency will verify system is filled with water to
minimum pressure and open air vents, if used, to expel any
air accumulated in the system. Check piping system and, if
leaks are found, have them repaired immediately.
Check and maintain circulators. Refer to circulator
manufacturer's instructions.
Inspect venting system at the start of each heating
season. Check vent pipe from boiler to chimney for signs of
deterioration by rust or sagging joints. Repair if necessary.
Remove vent pipe at base of chimney or flue and using
mirror, check vent for obstruction and verify vent is in good
working order.
Inspect boiler flue gas passageways by a light and mirror.
Remove burner door. Place trouble lamp in flue collector
through draft relief opening. With mirror positioned above
burners, flue gas passageways can be checked for soot or
scale. See Figure 15.
Follow the following procedure to clean flue gas
passageways:
1.
Remove burners from combustion chamber by raising
burners up from manifold orifices and pulling toward
front of boiler. See Figure 17, Page 22.
2.
Disconnect vent pipe from draft hood.
3.
Remove top jacket panel.
4.
Remove combination flue collector and draft hood from
boiler castings by loosening nuts on hold down bolts
located on each side of collector. See Figure 15.
5.
Place sheet of heavy paper or similar material over
bottom of base and brush down flue passageways. Soot
and scale will collect on paper and is easily removed
with the paper.
6.
With paper still in place in base, clean top of boiler
castings of boiler putty or silicone used to seal between
castings and flue collector. Verify chips are not lodged
in flue passageways.
When cleaning process is complete, restore boiler
components to their original position. Use IS-808 GE
silicone to seal around flue collector and boiler castings.
13 - NORMAL SEQUENCE OF OPERATION
14 - GENERAL INSTRUCTIONS
Figure 15
- Blocked Vent Safety Switch, Roll-out
Safety Switch
Rollout Switch 4
Section Boiler
Rollout Switch
2,3,5,6,7
Section Boiler
*
P/N IM-BWBB-01
[240011111 REV C, 03/31/2017]
*
Burner shipping retention clips (not shown) may be removed if desired.
