AERCO Esteem Boiler with EZ-Set Controller - Manual (Page 35)

GF-135
Esteem 399 Low NOx Boiler Chapter 5
OMM-0089_0A Installation, Operation & Maintenance Manual Boiler Piping
NOTE
To ensure an adequate flow rate through the Esteem boiler, the
boiler supply and return piping size must be a minimum 1-1/2
inches.
5.13 SYSTEM PIPING - ZONE VALVES
Connect the Esteem boiler to the system piping as shown in Figure 5-6 when zoning with zone valves.
The primary / secondary piping ensures that the boiler loop has sufficient flow.
5.14 SYSTEM PIPING - THROUGH BOILER
In new or retrofit applications in which primary/secondary arrangement is not used, the Esteem boiler
allows this flexibility due to a lower boiler pressure drop, see the charts in Figure B-1 and B-2 in
Appendix B.
Figure 5-7 illustrates a multiple zone valve system with a single system/boiler circulator. A by-pass
loop with a pressure differential valve must be installed on the system piping.
Figure 5-8 illustrates a single zone utilizing the boiler circulator as the system circulator.
5.15 SYSTEM PIPING - RADIANT HEATING
The heat exchanger design of the Esteem 399 Low NOx boiler allows operation in a condensing
mode. This feature requires no return water temperature regulation in radiant heating
applications.
The design and construction of the Esteem heat exchanger allows the installation of the boiler
on systems with non-oxygen barrier tubing.
CAUTION
DO NOT install a water storage tank along with the unit in
systems with non-oxygen barrier tubing. Failure to comply
could result in premature failure of the storage tank.
A high temperature limit should be installed to ensure that the primary supply temperature does
not exceed the maximum allowable temperature for the radiant tubing.
The addition of the high temperature limit is important if the Esteem boiler is connected to a
domestic hot water system, which requires a high primary supply water temperature.
Size the system piping and circulator to provide the flow needed for the radiant system.
NOTES
• To ensure an adequate flow rate through the Esteem 399 Low
NOx boiler, the boiler supply and return piping size must be a
minimum of 1-1/2” (inches).
• The addition of the high temperature limit is important if the
Esteem boiler is connected to a domestic hot water system,
which requires a high primary supply water temperature.
Page 35 of 188 AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 OMM-0089_0A
MC1 06/19/14 Ph.: 800-526-0288