AERCO BMK 3.0 LN Natural Gas July 2011 - Manual (Page 55)

MAINTENANCE
7-3
7.3 FLAME DETECTOR
The flame detector, part no. 66006, is located in
the body of the burner (see Figure 7-1). The
flame detector may be HOT. Allow the unit to
cool sufficiently before removing the flame
detector.
To inspect or replace the flame detector:
1. Set the ON/OFF switch on the control panel,
to the OFF position. Disconnect AC power
from the unit.
2. Remove the top panels from the unit.
3. Disconnect the lead wire from the flame
detector.
4. Remove the two (2) screws securing the
flame detector to the burner housing (Figure
7-1). The flame detector is secured to the
burner housing with one (1) #10-32 screw
and one (1) #8-32 screw.
5. Remove the flame detector and gasket from
the burner housing.
6. Inspect the detector thoroughly. If eroded,
the detector should be replaced. Otherwise
clean the detector with a fine emery cloth.
7. Reinstall the flame detector and flame
detector gasket.
8. Reconnect the flame detector lead wire.
9. Reinstall the top and side panels on the unit.
7.4 COMBUSTION CALIBRATION
Combustion settings must be checked at the
intervals shown in Table 7-1 as part of the
maintenance requirements. Refer to Chapter 4
for combustion calibration instructions.
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 INSPECTION
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 replacement parts will be
necessary for reassembly following inspection:
Part No. Description
81030 Burner Gaskets (Qty=2)
81048 Flame Detector 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 (see Figure 7-1).
4. Remove the two (2) screws securing the
flame detector to the burner housing. The
flame detector is secured to the burner
housing with one (1) #10-32 screw and one
(1) #8-32 screw.
5. Remove the flame detector and gasket from
the burner housing.
6. Disconnect the cable from the ignitor-injector.
7. Using a 7/16” open-end wrench, disconnect
the compression nut securing the gas injector
tube of the ignitor-injector to the elbow of the
staged ignition assembly. Disconnect the
staged ignition assembly from the ignitor-
injector.
8. Loosen and remove the ignitor-injector from
the burner plate using a 1" wrench.
9. Disconnect the burner housing from the
blower by removing the six (6) 1/4-20 screws
using a 3/8” wrench.
10. Remove the eight (8) 3/8-16 nuts from the
burner flange (Figure 7-3) using a 9/16”
wrench.