Table of Contents
Advertisement
On call for heat, thermostat will actuate, completing
the circuit to control. Completed circuit to control will
fi rst activate the circulator and damper which will
close an end switch inside the damper. This action
will complete the circuit to the ignition system and
ignition will take place.
In event the boiler water temperature exceeds high
limit setting on boiler mounted high limit control,
power will be interrupted between control system
and ignition system. Power will remain off until
boiler water temperature drops below high limit
setting. Circulator will continue to operate under this
condition until thermostat is satisfi ed.
In event fl ow of combustion products through boiler
venting system becomes blocked, the blocked vent
safety switch will shut main burner gas off. Similarly, if
boiler fl ue-way becomes blocked, fl ame rollout safety
switch will shut main burner gas off. Figure 19.
If either of these conditions occur, DO NOT
ATTEMPT TO PLACE THE BOILER BACK INTO
OPERATION. CONTACT A CERTIFIED SERVICE
AGENCY.
Before seasonal start-up, have a certifi ed service agency
check the boiler for soot and scale in the fl ues, clean the
burners and check the gas input rate to maintain high
operating effi ciency.
Label all wires prior to disconnection when
!
servicing controls. Wiring errors can cause
improper and dangerous operation.
Verify proper operation after service.
The service agency or owner should make certain the
system is fi lled with water to minimum pressure and
open air vents, if used, to expel any air that may have
accumulated in the system. Check the entire piping system
and, if any leaks appear, have them repaired.
Circulators need to be checked and maintained.
Refer to the circulator manufacturer's instructions.
The venting system should be inspected at the start of each
heating season. Check the vent pipe from the boiler to the
chimney for signs of deterioration by rust or sagging joints.
Repair if necessary. Remove the vent pipe at the base of
the chimney or fl ue and using a mirror, check vent for
obstruction and make certain the vent is in good working
order.
NORMAL SEQUENCE OF OPERATION
GENERAL INSTRUCTIONS
CAUTION
Figure 19
The boiler fl ue gas passageways may be inspected by a
light and mirror. Remove the burner door. (Figure #20)
Place a trouble lamp in the fl ue collector through the
draft relief opening. With the mirror positioned above the
burners, the fl ue gas passageways can be checked for soot
or scale.
The following procedure should be followed to clean the
fl ue gas passageways:
Remove the burners from the combustion chamber by
1.
raising the burners up from the manifold orifi ces and
pulling toward the front of the boiler. Figure 21.
Disconnect the vent pipe from the draft hood.
2.
Remove the top jacket panel.
3.
Remove the combination fl ue collector and draft hood
4.
from the boiler castings by loosening the nuts on the
hold down bolts located on each side of the collector.
Figure 19.
Place a sheet of heavy paper or similar material over
5.
the bottom of the base and brush down the fl ue
passageways. The soot and scale will collect on the
paper and is easily removed with the paper.
With the paper still in place in the base, clean the top
6.
of the boiler castings of the boiler putty or silicone
used to seal between the castings and fl ue collector.
Make certain that chips are not lodged in the fl ue
passageways.
21
Advertisement
Table of Contents
