BMK 750-3k Platinum Boiler OPERATION, SERVICE, and MAINTENANCE GUIDE
SECTION 5 – MAINTENANCE
OMM-0116_0A
AERCO International, Inc.
•
100 Oritani Dr.
•
Blauvelt, NY 10913
Page
59
of
178
GF-201
Ph.: 800-526-0288
03/15/2017
5.3 FLAME DETECTOR
The flame detector (kit P/N
24356-1
) is located on the burner plate at the top of the unit (see
Figures 5-1a through 5-1c and 5-2a through 5-2c). The flame detector may be hot. Allow the
unit to cool sufficiently before removing the flame detector. Inspect or replace the flame detector
as follows:
FLAME DETECTOR MAINTENANCE Instructions
1. Set the control panel ON/OFF switch to the
OFF
position. Disconnect AC power from the
unit.
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 flame detector lead wire.
4. Remove the two (2) screws securing the flame detector to the plate (Figure 5-2a – 5-2c).
5. Remove the flame detector and gasket from the burner plate.
6. Thoroughly inspect the flame detector. 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 shroud on the unit.
5.4 O
2
SENSOR
The Lean Oxygen Sensor (P/N
61026
) is located on the burner plate at the top of the unit (see
Figures 5-1a through 5-1c and 5-2a through 5-2c). The sensor may be hot. Allow the unit to cool
sufficiently before removing or replacing the O
2
sensor.
O
2
SENSOR MAINTENANCE Instructions
1. Set the ON/OFF switch on the control panel, to the OFF position. Disconnect AC power
from the unit.
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 O
2
sensor lead wire by pushing in on the release tab and pulling apart the
connector.
4. Next, loosen and remove the O
2
sensor and crush washer from the burner plate using a
15/16" open-end wrench.
5. Thoroughly inspect the O
2
sensor. If eroded, the sensor should be replaced. Otherwise
clean the sensor with a fine emery cloth.
6. Reinstall the O
2
sensor and crush washer on the burner plate.
7. Reconnect the sensor lead wire.
8.
Reinstall the shroud on the unit.
NOTE:
If the AERtrim technology system is functioning, it should be inspected at the same time as
O
2
sensor maintenance. See Section 4:
AERtrim Operation
, above, for instructions.
