User Guide

On-Demand Rack System • 5
INSTALLATION
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The clearance hole in each
moun ng bracket is 1/2-inch in
diameter. Fasteners must be
appropriate for the weight of the
rack and the material to which
it is being mounted. When
in doubt, consult a licensed
structural engineer.
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Use a leveling tool to make sure
that the assembly is level. To
operate properly, the assembly
must be level and the water
heaters must be in an upright
posi on (as shown in
Figure 3,
page 6).
Free Standing Rack
A. Before you begin, read all warnings
and bullet points at the beginning of
this sec on.
B. Place the rack and ensure that it is
level.
NOTICE:
You may need to use straps to
ensure that the li ing force is
ver cal.
C. Verify that the clearance
requirements are met. (Refer to the
water heater manual and applicable
code.)
D. Anchor the rack to the fl oor at each
leg. It must be secure and must not
allow movement.
NOTICE: The clearance hole in each
leg is 1/2-inch in diameter. Fasteners
must be appropriate for the material
to which the rack is being mounted.
When in doubt, consult a licensed
structural engineer.
Mul -Unit Controller
If your installation includes more than
four water heaters, you will need to
install a multi-unit controller. See the
configuration section on page 7 for
more information.
Piping Requirements
• Piping for up to six water heaters:
A rack system is designed with piping
to handle up to six water heaters. If
the job requires four to six heaters
in more than one format, then you
can use two racks that provide the
sum total of the required number of
heaters. For example, if you needed
fi ve heaters total, you could install a
rack with three heaters and another
with two heaters. The water lines
and gas line can be joined on site.
• Piping for six or more water
heaters: If the job requires mul ple
racks that total more than six water
heaters, refer to the piping diagram
on page 9. Mul ple rack systems
require a reverse return setup to
balance fl ows across the system.
Size the hot and cold headers that
supply the rack systems so that they
can accommodate the water volume
that is required. (These headers
will be larger than the rack system
piping.) The gas supply lines should
be sized to supply the maximum
input of the total number of water
heaters. Follow proper trade
prac ces and refer to ANSI Z223.1/
NFPA 54 (current edi on) for proper
sizing.
2
Install the Water
Supply
Once flow direction has been determined
and the inlet and outlet sides are known,
cap the open end of each manifold. See
Figure 3 on page 6. (Copper end
caps are not furnished.)
Install the water supply in reverse
return format. The flow direction
must preserve the “last in, first out”
principle of a reverse return. See
Figure 5 on page 9.
Flush the water line at each water
heater to remove debris, then purge
the air from each line. Failure to do
so may cause damage to the water
heaters.
3
Install the
Pressure Relief
Discharge Lines
• The discharge lines must be
installed according to the water
heaters’ Installation Manual and
Owner’s Guide.
•
The discharge piping for each
pressure relief valve must be
directed so that the hot water
cannot splash on anyone or on
nearby equipment.
• A ach each discharge pipe to the
pressure relief valve and run the end
of the tube to a maximum of 6 in. (152
mm) from the fl oor. This discharge
tube must allow free and complete
drainage without any restric ons.
• For indoor installa on, a drain pan,
or other means of protec on against
water damage, is required to be
installed under the water heaters in
case of leaks.
•
Follow all applicable code
requirements.