Aerco BENCHMARK 2500DF User Manual page 97

Benchmark 2500DF-3000DF Installation, Operation & Maintenance Manual
Burner Assembly Inspection and Maintenance Procedures - Continued
12. Remove the blower plenum from between the blower and the burner and set aside for
later reassembly. O2 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 (see Figure 7-5).
During reassembly, apply a light coating of high-temperature, anti-
seize lubricant to the threads of the igniter-injector and grounding
screw. Also, ensure that the igniter-injector is properly positioned
as indicated in Figure 7-3. Torque the igniter-injector to 170 - 180
in-lbs.
15. Beginning with the burner assembly, reinstall all the components in the reverse order that
they were removed. When reinstalling the blower plenum (removed in step 11), tighten the
3/8-16 nuts using a typical torque pattern (for example, loosely tighten one nut, then
loosely tighten a second nut on the opposite side, a third at 90 degrees to the first two,
and a fourth opposite the third, and then repeat this pattern with the remaining four nuts.
Repeat the entire pattern a second time to partially tighten all eight nuts, and then repeat
a third time until all eight nuts are fully torqued to 35 ft. lbs).
16. Ensure that the igniter-injector and flame detector cutouts in the burner plate are properly
aligned with the heat exchanger top flange.
OMM-0099_0A
GF-145
CHAPTER 7 – MAINTENANCE
NOTE
The burner assembly weighs approximately 65 lbs.
NOTE
AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913
Ph.: 800-526-0288
Page 97 of 234
PR1: 05/21/2014