Flame Detector; O 2 Sensor - Watts AERCO Benchmark OMM-0121 Operation And Maintenance Manual

Benchmark 750-3000 Boiler Operation & Maintenance Manual
SECTION 4 – MAINTENANCE

4.3 FLAME DETECTOR

The flame detector (kit P/N 24356-1) is located on the burner plate at the top of the unit (see
Figure 4-1a through 4-1c and 4-2a through 4-2c, above). 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 C-More Controller's 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 4-2a – 4-2c).
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.
4.4 O SENSOR
2
The Lean Oxygen Sensor (P/N 61026) is located on the burner plate at the top of the unit (see
Figure 4-1a through 4-1c and Figure 4-2a through 4-2c). The sensor may be hot. Allow the unit
to cool sufficiently before removing or replacing the O
O Sensor Maintenance Instructions
2
1. Set the ON/OFF switch on the C-More Controller 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 sensor lead wire by pushing in on the release tab and pulling apart the
2
connector.
4. Next, loosen and remove the O
15/16" open-end wrench.
5. Thoroughly inspect the O
clean the sensor with a fine emery cloth.
6. Reinstall the O sensor and crush washer on the burner plate.
2
7. Reconnect the sensor lead wire.
8. Reinstall the shroud on the unit.
OMM-0122_D • GF-206 • 5/9/2019
sensor and crush washer from the burner plate using a
2
sensor. If eroded, the sensor should be replaced. Otherwise
2
Technical Support • (800) 526-0288 • Mon-Fri, 8 am - 5 pm EST
sensor.
2
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