Site Location - A.O. Smith On Demand 305 Series 100 Design Manual

In addition to using the lowest possible temperature setting that satisfies your hot water needs, a means
such as a mixing valve, should be used at hot water taps used by these people or at the water heater.
Mixing valves are available at plumbing supply or hardware stores. Follow manufacturer's instructions for
installation of the valves. Before changing the factory setting on the thermostat see table below. Using
the lowest hot water temperature that meets your needs will also provide the most energy efficient oper-
ation of the water heater.
Never allow small children to use a hot water
tap, or to draw their own bath water. Never
leave a child or handicapped person un-
attended in a bathtub or shower.
NOTE: A water temperature range of 120
140 ° F (49 ° C-60 ° C) is recommended by most
dishwasher manufacturers.
The thermostat of the water heater has been factory set at 120
adjustable and can be reset to the desired temperature setting. Some states have a requirement for a
lower setting. If you need hotter water, follow directions for temperature adjustment, but beware of the
warnings in this section.

Site Location

• Select a location near the center of the water piping system.
• Consider the exhaust vent system piping and combustion air supply requirements when selecting the
water heater location. The venting system must be able to run from the water heater to the termina-
tion with a minimal length and number of elbows.
• Locate the water heater near the existing gas piping. If installing a new gas line, locate the water
heater to minimize the pipe length and elbows.
NOTE: This water heater must be installed according to all
local and state codes or, in the absence of local and state
codes, the "National Fuel Gas Code", ANSI Z223.1(NFPA
54)-current edition.
• The water heater should be located in an area not subject to freezing temperatures. Water heaters
located in unconditioned spaces (i.e., attics, basements, etc.) may require insulation of the water piping
and drain piping to protect against freezing. The drain and controls must be easily accessible for oper-
ation and service. Maintain proper clearances as specified on the data plate.
Installation
Temperature
Settings
160°F (71°C)
150°F (66°C)
140°F (60°C)
° F -
130°F (54°C)
120°F (49°C)
80°F (27°C)
° F, to reduce the risk of scald injury. It is
5
Time to Produce 2nd & 3rd
Degree Burns on Adult Skin
About 1/2 second
About 1-1/2 seconds
Less than 5 seconds
About 30 seconds
More than 5 minutes
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Table "A"