Basic Installation & Operation - A.O. Smith 12 40GPC T 100 Service Handbook

INSTALLATION OF RESIDENTIAL GAS WATER HEATER
See Labels and
Installation Instructions
and Use & Care Guide
for clearances.
Use Draft Hood
supplied with unit
To Fixtures - Hot
Tempered Water
To Fixtures
Untempered
Cold
Hot Water
Water
Inlet
Hot
Water
Outlet
Mixing Valve
(Set to 120°F)
Follow the Mixing Valve
Manufacturer's Instructions
Union
Sediment Trap
(Drip Leg) 3" Minimum.
The 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.
* NOTE: If on a well system the expansion tank should be set to the maximum pressure of the pump tank.
** White-Rodgers® gas control valve/thermostat shown in this figure.
BASIC INSTALLATION & OPERATION
Exhaust Vent to
Ouside of Building
Union
Union
Gas
Supply
Control
Display
FV Sensor
Bracket
Water
Shut-Off
Valve
Temperature-Pressure Relief Valve
with discharge piped to an
adequate drain. Do not cap or plug.
Manual Gas Shut-off Valve
Air is drawn in for combustion.
Keep area clean and free from
flammables and flammable vapors.
Metal Drain Pan piped to an adequate drain.
NOTE: Drain pan diameter must be at least
2 inches wider than the diameter of the
water heater.
Figure 1
6
Water
Supply- Cold*
*Massachusett: Install
a vacuum relief in cold
water line per section
19 MGL 142.
Expansion Tank
Pressurize to Equal
Supply Water Pressure*
(Relieve water pressure
on the expansion tank
before adjusting air
pressure.)
Air Intake Chamber
Gas Control Valve/Thermostat
Recommended setting of 120°F.**
Do not cap or plug.
6" Maximum Air Gap
NOTE: Local codes
may vary.
Drain
Electrical Plug