Watts AERCO Benchmark OMM-0136 - O 2 Sensor

Benchmark Platinum-Edge [II]: Operation-Service Manual
SECTION 8 – MAINTENANCE
OMM-0137_E • GF-211 • 12/13/2019 Technical Support • (800) 526-0288 • Mon-Fri, 8 am - 5 pm EST Page 109 of 153
The flame detector should be inspected every 12 months and replaced every 24 months, or
sooner if damaged or warped. Note, it may be hot; allow the unit to cool sufficiently before
removing the flame detector.
Be sure to use the current model flame detector, included in the maintenance kit; some older
flame detectors are shaped differently and may not function properly.
This part and instructions are included in both 12 Month Maintenance Kit P/N 58025-01 (BMK750
–3000) and P/N 58025-11 (BMK5000 & 6000) and all BMK750 – 6000 24 Month Maintenance
Kits.
8.5 O
2
SENSOR
The Lean Oxygen Sensor (P/N 61026) should be cleaned and inspected every 12 months. It is
not included in any of the 12- or 24-month maintenance kits.
On BMK750 – 4000 units, it is located on the burner plate at the top of the unit. It may be hot, so
allow the unit to cool sufficiently before removing or replacing the it.
Figure 8-3a: O
2
Sensor Mounting Location – BMK750 – 4000 (BMK750 shown)
On the BMK5000 & 6000, it is located on the burner’s rear plate, on the rear of the unit.
REAR OF UNIT
O
2
SENSOR
O
2
SENSOR
(P/N 61026)
GAS LINE TO
EXHAUST
MANIFOLD
AIR EDUCTOR
ASSY.
For AERtrim
(P/N 24508-TAB)
O
2
SENSOR
COVER
(Removed from
original position)