Fuel Types And Combustion Calibration; Combustion Calibration - Watts AERCO Benchmark BMK750 Operation And Service Manual

Benchmark with Edge [I]: Operation-Maintenance Manual
SECTION 4 – INITIAL START-UP

4.3 FUEL TYPES and COMBUSTION CALIBRATION

All BMK models are preconfigured at the factory to use either natural gas or propane gas, and
BMK models 1500 to 6000 are available in dual fuel versions (natural gas and propane).
Both fuel types require different combustion calibration values, and so care must be taken to
ensure to follow the instructions for the fuel being used.
•
Natural Gas combustion calibration: Section 4.4.1
•
Propane combustion calibration: Section 4.4.2
Instructions for switching between fuel types in dual fuel models are presented in Section 4.6.

4.4 COMBUSTION CALIBRATION

The Benchmark boiler is combustion calibrated with either standard combustion (NOx emissions
of <20 ppm) or Ultra-Low NOx (NOx <9 ppm) on the BMK750 to 2000 only at the factory,
whichever was ordered, prior to shipping. The gas pressure must be within the ranges shown in
Table 4-2 for each model of boiler at full fire.
Recalibration as part of initial start-up is necessary due to changes in the local altitude, gas BTU
content, gas supply piping and supply regulators. Combustion Calibration Test Data sheets are
shipped with each unit. These sheets must be filled out and returned to AERCO for proper
Warranty Validation.
IT IS IMPORTANT TO PERFORM THE COMBUSTION CALIBRATION PROCEDURE BELOW
TO PROVIDE OPTIMUM PERFORMANCE AND KEEP READJUSTMENTS TO A MINIMUM.
Figure 4-3: Gas Pressure Adjustment Screw and TAC Screw Location
OMM-0145_A99 • GF-218 •
BRASS HEX HEAD
(Remove to access
Gas Pressure
Adjustment Screw).
Technical Support • (800) 526-0288 • Mon-Fri, 8 am - 5 pm EST
9/18/2019
TAC SCREW
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