Sediment Traps; Filling The Water Heater; Venting; Vent Pipe Termination - A.O. Smith RESIDENTIAL GAS WATER HEATERS Instruction Manual

sedIMent traps

A sediment trap shall be installed as close to the gas inlet of the water
heater as practical at the time of water heater installation. The sediment
trap shall be either a tee fitting with a capped nipple in the bottom outlet
or other device recognized as an effective sediment trap.
Contaminants in the gas lines may cause improper operation of the
gas control valve that may result in fire or explosion. Before attaching
the gas line be sure that all gas pipe is clean on the inside. To trap any
dirt or foreign material in the gas supply line, a drip leg (sometimes
called a sediment trap) must be incorporated in the piping. The drip
leg must be readily accessible. Install in accordance with the "Gas
Piping" section. Refer to the current edition of the National Fuel
Gas Code (ANSI Z223.1/NFPA 54) or the Natural Gas and Propane
Installation Code (CAN/CSA B149.1).

fIllInG the water heater

Never use this water heater unless it is completely full of water. To prevent
damage to the tank, the tank must be filled with water. Water must flow
from the hot water faucet before turning "ON" gas to the water heater.
To fill the water heater with water:
1. Close the water heater drain valve by turning the handle to the right
(clockwise). The drain valve is on the lower front of the water heater.
2. Open the cold water supply valve to the water heater.
note: the cold water supply valve must be left open when
the water heater is in use.
3. To insure complete filling of the tank, allow air to exit by opening the
nearest hot water faucet. Allow water to run until a constant flow is
obtained. This will let air out of the water heater and the piping.
4. Check all water piping and connections for leaks. Repair as needed.

ventInG

vent pIpe terMInatIon

The first step is to determine where the vent pipe will terminate.
See Figures 19, 20, and 21. The vent may terminate through a
sidewall as shown in Figure 19 or through the roof as shown in
Figures 20 and 21.
The vent system must terminate so that proper clearances
are maintained as cited in local codes or the current
edition of the National Fuel Gas Code, (ANSI Z223.1, 12.9.1
through 12.9.4) or the Natural Gas and Propane Installation
Code (CAN/CSA-B149.1).
Instructions on proper installation through a sidewall are provided
in Figures 15A, 15B, 15C, and 15D.
Plan the vent system layout so that proper clearances are
maintained from plumbing and wiring.
Vent pipes serving power vented appliances are classified by
building codes as "vent connectors". Required clearances from
combustible materials must be provided in accordance with
information in this manual under FACTS TO CONSIDER ABOUT
LOCATION and INSTALLING THE WATER HEATER, and with
the National Fuel Gas Code and local codes.
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