Flue Exhaust Piping To Vent - Watts AERCO Modulex EXT Commercial Series User Manual

Modulex EXT Commercial Series Boilers User Manual
CHAPTER 4: Installation Instructions

4.19 FLUE EXHAUST PIPING TO VENT

In a condensing boiler the flue exhaust is evacuated at a very low temperature (maximum of
about 183°F / 84°C). Thus, it is necessary that the chimney be impermeable to the condensate
of the combustion products and be made of corrosion resistant materials.
The different joints must be well sealed and equipped with suitable gaskets in order to prevent
the escape of condensate and prevent the ingress of air.
To determine the proper cross section and height dimensions of the flue exhaust piping, refer to
national and local codes.
In order to prevent the formation of ice during the operation, the temperature of the internal wall
of the flue exhaust system should not be below 32 °F (0 °C) throughout its length.
For efficient venting of the combustion exhaust and to address condensation due to lower
external temperatures, ensure that combustion condensation is discharged into the boiler
condensate tray or into another separate collection pan according to the installation.
A test nipple, for measuring combustion gases, should be installed onto the first three feet of the
exhaust manifold flue. To do this, a hole with a diameter of 0.83'' is drilled in a convenient
location for testing and the test nipple hardware assembled to the Flue pipe as shown in Figure
4-13.
Figure 4-13: Installation of Test Nipple into Flue Manifold Piping
NOTE:
Damage caused by mistakes in installation, failure to complete the instructions as written, or the
improper use of the flue system are not the responsibility of the supplier.
OMM-0095_0H AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 Page 41 of 144
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