Navien NPN Installation & Operation Manual page 18

Proximity to fixtures and appliances
Install the water heater near fixtures that deliver
or use hot water, such as bathroom, kitchen,
and laundry room faucets. Select a location that
minimizes the water piping required between major
fixtures. If the distances are long or if the water
heater requires "instant" hot water, we recommend
running a recirculation line back to the water heater
from the furthest fixture. Insulate as much of the hot
water supply and recirculation lines as possible. For
more information about the water supply, refer to
"3.4 Connecting the Water Supply" on page 25.
Adequate installation clearances
Install the water heater in an area that allows
for service and maintenance access to utility
connections, piping, filters, and traps. Based on the
installation location, ensure the following clearances
are maintained:
For indoor installation
Clearance
to Combustibles
from:
6 in (152 mm)
Top
minimum
0 in (0 mm)
Back
minimum
6 in (152 mm)
Front
minimum
2 in (51 mm)
Sides
minimum
Ground/ 12 in (305 mm)
Bottom minimum
0 in (0 mm)
Vent
minimum
to Non-
Combustibles
2 in (51 mm)
minimum
0 in (0 mm)
minimum
6 in (152 mm)
minimum
1/2 in (13 mm)
minimum
12 in (305 mm)
minimum
0 in (0 mm)
minimum
For outdoor installation
Clearance
to Combustibles
from:
12 in (305 mm)
Top
minimum
0 in (0 mm)
Back
minimum
Front 24 in (610 mm)
(panel) minimum
Front 24 in (610 mm)
(exhaust) minimum
6 in (152 mm)
Sides
minimum
Ground/ 12 in (305 mm)
Bottom minimum
Clean, debris and chemical-free
combustion air
Do not install the water heater in areas where
●
dust and debris may accumulate or where hair
sprays, spray detergents, chlorine, or similar
chemicals are used.
Do not install the water heater in areas where
●
gasoline or other flammables are used or stored.
Ensure that combustible materials are stored
●
away from the water heater and that hanging
laundry or similar items do not obstruct access to
the water heater or its venting.
The combustion air must be free
Note
of flammable vapors or corrosive
chemical fumes. Common
corrosive chemical fumes to
avoid include fluorocarbons and
other halogenated compounds
such as Freon, trichloroethylene,
perchlorethylene, chlorine, which
can be found in refrigerants or
solvents. When these chemicals
burn, they produce acids that
corrode the stainless steel heat
exchanger, gaskets, and the flue
and vent system.
In commercial locations, do not install the water
●
heater in areas with greasy fumes or heavy
amounts of steam or take measures to prevent
fumes and steam from entering the water heater.
to Non-
Combustibles
2 in (51 mm)
minimum
0 in (0 mm)
minimum
0 in (0 mm)
minimum
24 in (610 mm)
minimum
1/8 in (3.2 mm)
minimum
2 in (51 mm)
minimum
Installing the Water Heater 17