11
110891-02 -5/22
RSAH
Installation & Service Manual
d. Use a system 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 3-3 and
3-4 in order to regulate water flow for
maintenance of higher boiler water
temperature. Set the bypass and return
valves to a half throttle position to start.
Operate boiler until the system water
temperature reaches its normal operating
range. Adjust the valves to maintain 180°F
to 200°F boiler water temperature and
greater the 120°F return temperature.
Adjust both valves simultaneously. Closing
the boiler return valve while opening the
bypass valve will raise the boiler return
temperature. Opening the boiler return
valve while closing the by-pass valve will
lower the boiler return temperature.
e. A water boiler installed above radiation level
must be provided with a low water cutoff
device as part of the installation.
B. INSTALL SAFETY RELIEF VALVE. See Figures
3-2, 3-3 and 3-4. Safety Relief Valve must be
installed with spindle in the vertical position.
Installation of the relief valve must be consistent
with ANSI/ASME Boiler and Pressure Vessel Code,
Section IV.
WARNING
Installation is NOT complete unless a safety
relief valve is installed as shown in Figure 5.
Safety (relief) valve discharge piping must
be piped near floor to eliminate potential of
severe burns. DO NOT pipe in any area where
freezing could occur. DO NOT install any shut-
off valves, plugs or caps.
C. AIR VENT. An air vent or purge must be
incorporated in the system to easily remove air
from the boiler when the system is filled. The
boiler has a built in dip tube which works with
the air vent to clear the boiler of air. Improper
application of the air vent will cause steaming in
the boiler. See Figures 3-2, 3-3 and 3-4.
D. INSTALL DRAIN VALVE in return piping. See
Figures 3-3 and 3-4.
E. OIL, GREASE, AND OTHER FOREIGN
MATERIALS which accumulate in new hot
water and a new or reworked system should
be boiled out, and then thoroughly flushed. A
qualified water treatment chemical specialist
should be consulted for recommendations
regarding appropriate chemical compounds and
concentrations which are compatible with local
environmental regulations.
Figure 3-2: Air Vent and Safety Relief Valve
Installation Detail
F. AFTER THE BOILER AND SYSTEM HAVE BEEN
CLEANED and flushed, and before refilling the
entire system add appropriate water treatment
chemicals, if necessary, to bring the pH between
7 and 11.
G. CONNECT TANKLESS HEATER PIPING AS
SHOWN IN FIGURE 3-5. See Table 3-6 for
Tankless Heater Rating.
WARNING
Install automatic mixing valve at tankless heater
outlet to avoid risk of burns or scalding due
to excessively hot water at fixtures. Adjust
and maintain the mixing valve in accordance
with the manufacturer’s instructions. DO NOT
operate tankless heater without mixing valve.
3
Water Piping and Trim
(continued)
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