MC2: 10/03/12 Page 38 of 90
AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 • Ph: 800-526-0288
Modulex MLX Series Gas Fired Boiler System
Operation and Maintenance Manual
Figure 7-2: Heat Mode Symbols
7.5.5 Combustion Calibration.
The Modulex boiler is combustion calibrated prior to shipment from the factory. However, AERCO
recommends that the following calibration and adjustments be performed due to possible differences in
altitude, BTU content, installed gas supply piping and regulators used.
In addition to checking the oxygen (O
2
), carbon dioxide (CO
2
) and carbon monoxide (CO) combustion
readings, this procedure also checks the gas valve outlet pressure for each boiler stage. This is
accomplished by connecting a 16” W.C. manometer (or gauge) to the Outlet Pressure Tap of each
boiler stage gas valve to check pressure while making adjustments.
To calibrate the combustion of the Modulex boiler, refer to Figure 7-3 below, and follow the instructions
on the next page.
NOTE
The manometer installed in following steps 1-4 will be moved, in turn, to
each boiler stage for calibration. Ensure that each outlet pressure tap for
each gas valve is fully closed (rotated fully clockwise) BEFORE
connecting the manometer to the next valve for calibration.
Figure 7-3: Gas Valve Offset Adjustment Screw and Outlet Pressure Tap
Pressure Tap Outlet
And Adjustment Screw
Exposed Offset
Adjustment Screw
(Detail at Right)
Pressure