Install Instructions

28
A. EVALUATE THE EXISTING WATER SYSTEM.
Design a piping system and install boiler which will
prevent oxygen contamination of boiler water and
frequent water additions.
1. There are many possible causes of oxygen
contamination such as:
a. Addition of excessive make-up water as a result
of system leaks.
b. Absorption through open tanks and ttings.
c. Oxygen permeable materials in the distribution
system.
2. In order to insure long product life, oxygen sources
must be eliminated. This can be accomplished by
taking the following measures:
a. Repairing system leaks to eliminate the need for
addition of make-up water.
b. Eliminating open tanks from the system.
c. Eliminating and/or repairing ttings which allow
oxygen absorption.
d. Use of non-permeable materials in the
distribution system.
e. Isolating the boiler from the system water by
installing a heat exchanger.
WARNING
System supply and return piping must be
connected to correct boiler pipe.
U.S. Boiler Company recommends sizing the
system circulator to supply sufcient ow
(GPM) to allow a 20°F temperature differen-
tial in the system. When sizing the system
circulator, the pressure drop of all radiators,
baseboard and radiant tubing and all connect-
ing piping must be considered.
CAUTION
Maintain minimum ½ inch clearance from hot
water piping to combustible materials.
B. CONNECT SYSTEM SUPPLY AND RETURN
PIPING TO BOILER. See Figures 15A and 15B.
Also, consult Residential Hydronic Heating Installation
and Design I=B=R Guide.
1. If this boiler is used in connection with refrigeration
systems, the boiler must be installed so that the
chilled medium is piped in parallel with the heating
boiler using appropriate valves to prevent the
chilled medium from entering the boiler. See Figure
14. Also, consult Residential Hydronic Heating
Installation and Design I=B=R Guide.
2. If this boiler is connected to heating coils located
in air handling units where they may be exposed
to refrigerated air, the boiler piping must be
equipped with ow control valves to prevent gravity
circulation of boiler water during the operation of
the cooling system.
3. If boiler is used with an Indirect Domestic
Water Heater, install the Indirect Water Heater
as a separate heating zone. Refer to the Indirect
Water Heater Installation, Operating, and Service
Instructions for additional information.
4. Use a boiler bypass if the boiler is to be operated
in a system which has a large volume or excessive
radiation where low boiler water temperatures may
be encountered (i.e. converted gravity circulation
system, etc.) The bypass should be the same size as
the supply and return lines with valves located in
the bypass and return line as illustrated in Figures
15A and 15B in order to regulate water ow for
maintenance of higher boiler water temperature.
WARNING
The use of a low water cut-off device, while not
required unless radiation level is below the boiler,
is highly recommended.
5. If a Low Water Cut-Off (LWCO) is required, it must
be mounted in the system piping above the boiler.
The minimum safe water level of a hot water boiler
is just above the highest water containing cavity of
the boiler; that is, a hot water boiler must be full of
water to operate safely. Refer to Appendix A at the
rear of this manual.
SECTION V: WATER BOILER PIPING AND TRIM
NOTICE
Failure to pipe boiler as specied in this manual may result in excessive system noise, water line uctuations
and water carry over.