A.O. Smith FMD 40 Manual Do Utilizador

Página de 56
7
FACTS TO CONSIDER ABOUT THE LOCATION
Whether replacing an old water heater or putting the water heater in 
a new location, the following critical points must be observed.
This manufactured home gas-fi red water heater is for use in a 
manufactured home. You should carefully choose an indoor location 
for the new water heater, because the placement is a very important 
consideration for the safety of your occupants in the building and 
for the most economical use of the appliance. This water heater 
is for use only in a manufactured home and not intended for 
outdoor installation.
This water heater has been designed and certifi ed as a direct vent 
(sealed combustion) unit and no draft diverter is to be used.
Minimum clearances between the water heater and combustible 
and noncombustible construction are 0” from sides, 0” from back, 
4” (10.16 cm)  from front of jacket to closet door and 27” (68.58 cm) 
from top of jacket to combustible material. Minimum vent clearances: 
6” (15.24 cm). Provide 24” (60.96 cm) front clearance for servicing 
and adequate clearance between the jacket top and ceiling for 
servicing the fl ue area.
The combustion and ventilation air fl ow must not be obstructed.
Combustion air must be supplied from outside the manufactured 
home by way of the furnished 3” diameter (30 Gallon [113.56 Liter] 
and 40 Gallon [151.42 Liter]) or 4” diameter (50 Gallon [189.27 Liter]) 
air intake duct assembly. A 3 1/2” (8.89 cm) diameter (30 Gallon 
[113.56 Liter] and 40 Gallon [151.42 Liter]) or 4 1/2” (11.436 cm) 
diameter (50 Gallon [189.27 Liter]) fl oor opening below the water 
heater is required to accommodate the air intake duct assembly. 
Weight of the water heater on duct gasket seals the water heater to 
air intake duct assembly.
When a manufactured home is skirted, an air intake opening with a 
minimum free area of 32 square inches (81.28 square cm) must be 
provided in the skirt. If the opening is covered by louvers or screen, 
the total free area must be 32 square inches (81.28 square cm). 
Other gas fi red appliance in the home will require additional free 
air openings; consult these manufacturers for correct sizing, see 
Figure 3.
FIGURE 3.
If the manufactured home is installed over a basement or crawlspace, 
combustion air must be supplied from outside the manufactured 
home. The combustion air intake piping can be 3” (7.62 cm) PVC for 
30 Gallon (113.56 Liter) and 40 gallon (151.42 Liter) models and 4” 
(10.16 cm) PVC for 50 Gallon (189.27 Liter) models. The air intake 
piping cannot exceed a total of 30 feet (9.14 m) including vertical 
LOCATING THE NEW WATER HEATER
and horizontal runs and have no more than 3 elbows. All horizontal 
runs require adequate support at 3 1/2 feet (106.68 cm) intervals., 
see Figure 4.
FIGURE 4.
The water heater should be secured to the fl oor and to the wall of the 
enclosure with the mounting brackets provided. For bracket location 
refer to Securing Water Heater to Floor and Wall” in the “Installing 
the New Water heater” section.
Installation of the water heater must be accomplished in such a 
manner that if the tank or any connections should leak, the fl ow 
will not cause damage to the structure.  For this reason, it is not 
advisable to install the water heater in an attic or upper fl oor.  When 
such locations cannot be avoided, a suitable metal drain pan should 
be installed under the water heater.  Metal drain pans are available 
at your local hardware store.  Such a metal drain pan must have a 
minimum length and width of at least 2 inches (51 mm) greater that 
the water heater dimensions and must be piped to an adequate drain.  
The pan must not restrict combustion air fl ow. When a metal drain 
pan is required, see installation instructions on page 9.
Water heater life depends upon water quality, water pressure and 
the environment in which the water heater is installed. Water heaters 
are sometimes installed in locations where leakage may result in 
property damage, even with the use of a metal drain pan piped to a 
drain. However, unanticipated damage can be reduced or prevented 
by a leak detector or water shut-off device used in conjunction with 
a piped metal drain pan.