Benchmark 2500 - 3000 Boilers
CHAPTER 7 – MAINTENANCE
Page
94
of
207
AERCO International, Inc.
•
100 Oritani Dr.
•
Blauvelt, NY 10913
OMM-0094_0F
09/30/2015
Ph.: 800-526-0288
GF-137
7.6 BURNER ASSEMBLY INSPECTION
The burner assembly is located at the top of the unit's heat exchanger. The burner assembly
may be hot. Therefore, allow the unit to cool sufficiently before removing the burner assembly.
The following parts will be required for reassembly after burner inspection:
Part No.
Description
88173
Burner Upper Release Gasket
81180
Burner Gasket (Middle)
81185
Burner Lower Release Gasket
81048
Flame Detector Gasket (1 each)
To inspect or replace the burner assembly, proceed as follows:
Burner Assembly Inspection and Maintenance Procedures
1. Set the ON/OFF
switch on the control panel, to the
OFF
position. Disconnect AC power
from the unit and turn off the gas supply.
2. Remove the top shroud from the unit by grasping the top handle and lifting straight up.
This will disengage the shroud from the four (4) pins in the side panels.
3. Disconnect the lead wire from the flame detector installed on the burner plate. See Figure
7-2.
4. Remove the two (2) screws securing the flame detector to the plate. The flame detector is
secured to the burner plate with one (1) #10-32 screw and one (1) #8-32 screw.
5. Remove the flame detector and gasket from the burner plate.
6. Disconnect the cable from the igniter-injector.
7. Using a 7/16” open-end wrench, disconnect the compression nut securing the gas
injector tube of the igniter-injector to the elbow of the staged ignition assembly (see
Figure 7-2). Disconnect the staged ignition assembly from the igniter-injector.
8. Next, loosen and remove the igniter-injector from the burner plate using a 1" open-end
wrench.
9. Loosen and remove the four 5/16x1-3/4” bolts, washers, and nuts from the blower plenum
where it is attached to the blower (see Figure 7-4a & 7-4b).
10.
You must either rig a support for the blower to hold it in place or remove the blower from
the unit and set it aside for later reassembly.
11. Remove the eight (8) 3/8-16 nuts attaching the blower plenum to the burner (see Figure
7-4a & 7-4b).
12. Remove the blower plenum from between the blower and the burner and set it aside for
later reassembly. The O
2
sensor and flame observation port remain assembled to the
plenum flange.
13. Remove the burner by pulling straight up.
14. Remove and replace the burner gasket(s) (see Figure 7-5).
NOTE
The burner assembly weighs approximately
65 lbs. (29.5 kg).