AERCO BMK 3.0 LN Nat. Gas APRIL 2009 - Manual (Page 53)

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
The burner assembly is located at the top front
of the unit. The burner assembly may be HOT.
Allow the unit to cool sufficiently before
removing the burner assembly.
The following parts will be necessary for
reassembly after inspection:
Part No. Description
81030 Burner Gaskets (Qty=2)
81047 Gas Injector Gasket (Qty=1)
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 burner housing from the
blower by removing the six (6) 1/4-20
screws using a 3/8” wrench.
7. Remove the eight (8) 3/8-16 nuts from the
burner flange (Figure 7-3) using a 9/16”
wrench.
NOTE
The burner housing is heavy, weighing
approximately 20 pounds.
8. Remove the burner housing from burner
flange by pulling straight up.
9. Remove the grounding screw.
10. If there is an extension ring around the
burner, remove it.
11. Remove the burner by pulling straight up.
12. Remove and replace the burner gaskets.
13. Beginning with the burner removed in step
11, reinstall all the components in the
reverse order that they were removed.
However, if the burner was replaced, follow
the instructions in step 14.
14. If the burner is being replaced, measure the
outside diameter (O.D.) of the new burner
flange. If the O.D. is approximately 13”, do
not reinstall the extension ring. However, if
the O.D. of the new burner flange is
approximately 12.4”, the extension ring must
be reinstalled.
15. Make sure to align the Spark Igniter (S/I)
and Flame Rod (F/R) slots in the burner with
the heat exchanger top head.
16. Check to ensure that the grounding screw is
reinstalled.
3/8-16 NUTS (8)
BURNER
HOUSING
BURNER
STAGED IGNITION
ASSEMBLY
GROUNDING
SCREW
1/4-20
SCREWS
(6)
10-32 SCREWS (2)
Figure 7-3
Burner Disassembly Diagram