Installation Manual

H-Series Demand Duo™ 2 Installation and Operation Manual 18
Air surrounding the water heater, venting, and
vent termination(s) is used for combustion and
must be free of any compounds that cause
corrosion of internal components. These include
corrosive compounds that are found in aerosol
sprays, detergents, bleaches, cleaning solvents,
oil based paints/varnishes, and refrigerants. The
air in beauty shops, dry cleaning stores, photo
processing labs, and storage areas for pool
supplies often contains these compounds.
Therefore, it is recommended to install as a direct
vent (use outside air for combustion). In
applications utilizing room air where there are
high levels of particulates, Rinnai offers a room
air screen. The water heater, venting, and vent
termination(s) should not be installed in any areas
where the air may contain these corrosive
compounds.
If you install the Demand Duo™ 2 in an area that
is known to have hard water or that causes scale
build-up, the water must be treated and may
require a more frequent flushing schedule.
This water heater includes a service indicator
(Service Soon, SS). When selected in the
parameter settings, an SS code will display on the
controller indicating that it is time to flush and
service the water heater. Scale build-up is
caused by hard water and can be accelerated if
the water heater is set at a temperature above
120°F.
Rinnai offers Southeastern Filtration’s
“ScaleCutter Water Conditioning System” that
offers superior lime scale prevention and
corrosion control by feeding a blend of control
compounds into the cold water supply.
Location Clearance
Top of tank
• 12 in. (305 mm)
• 0 in. from vent components
• Clearance for servicing the
anode rods is 54 in. (1.4 m)
from top of water heater
Bottom
(Ground)
0 in.
Back of tank 0 in.
Front of tank-
less water
heaters
0 in.
Clearance for servicing is 24
in. (610 mm)
Sides (Left and
Right) of tank-
less water
heaters
2 in. (51 mm)
12 in. (305 mm)
2 in. (51 mm)
24 in. (610 mm)