Use and Care Manual

11
110637-01 - 5/20
RRO Installation & Service Manual
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 fittings.
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 fittings 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 sufficient
flow (GPM) to allow a 20°F temperature
differential in the system. When sizing the
system circulator, the pressure drop of all
radiators, baseboard and radiant tubing and all
connecting 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 4-2 and
4-3. 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
4-1. 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 flow 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 4-2 and 4-3 in order to regulate water
flow 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.
6. If it is required to perform a long term
pressure test of the hydronic system,
the boiler should first be isolated to avoid a
pressure loss due to the escape of air trapped
must first be removed from the boiler.
4 Water Boiler Piping and Trim
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