AERCO BMK 1.5 LN May 2009 - Manual (Page 51)

MAINTENANCE
7-3
7.5 SAFETY DEVICE TESTING
Systematic and thorough tests of the operating
and safety devices should be performed to
ensure that they are operating as designed.
Certain code requirements, such as ASME
CSD-1, require that these tests be performed on
a scheduled basis. Test schedules must
conform to local jurisdictions. The results of the
tests should be recorded in a log book. See
Chapter 6-Safety Device Testing Procedures.
7.6 BURNER ASSEMBLY
The burner assembly (part no. 24012) is located
at the top of the unit. The burner assembly may
be HOT. Allow the unit to cool sufficiently before
removing the burner assembly.
It should be noted that the complete burner
assembly also includes the blower and air/fuel
valve in addition to the Benchmark 1.5 low NOx
burner. It can be removed as one complete
assembly.
The following parts will be necessary for
reassembly after inspection:
Part No. Description
81063 Burner Gaskets (Qty=2)
81047 Gas Injector Gasket (Qty=1)
81064 Blower Gasket
To inspect or replace the burner assembly:
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 side and top panels from the
unit.
3. Disconnect the lead wire from the flame
detector. Unscrew the flame detector.
4. Disconnect the igniter cable from the igniter
contactor. Unscrew the igniter.
5. Remove the two (2) 10-32 screws securing
the gas injector to the burner. Separate the
gas injector and gasket from the burner.
6. Disconnect the gas train from the air/fuel
valve by removing the four 1/2” screws.
7. Disconnect the flex hose from the air/fuel
valve by loosening the hose clamp.
8. Remove the eight (8) 3/8-16 nuts from the
burner flange (Figure 7-3) using a 9/16”
wrench.
NOTE
The burner assembly is heavy, weighing
approximately 25 pounds.
9. Remove the burner assembly from burner
flange by pulling straight up.
10. Remove the grounding screw.
11. Remove and replace the burner gaskets.
12. Beginning with the burner assembly
removed in step 9, reinstall all the
components in the reverse order that they
were removed.
13. Make sure to align the S/I and F/R slots in
the burner with the heat exchanger top
head.
14. Check to ensure that the grounding screw is
reinstalled.
AIR/FUEL
VALVE
PARTIAL TOP VIEW
SPARK
IGNITER
FLAME
DETECTOR
STAGED
IGNITION
ASSEMBLY
GAS
TRAIN
BURNER
PLATE
BLOWER
3/8-16
NUTS (8)
Figure 7-3
Burner Disassembly Diagram