Start Up; Prior To Start Up; Lighting And Operation Labels - A.O. Smith 300 Series Instruction Manual

PRIOR TO START UP

Installation and start up of this water heater requires abilities and
skills equivalent to that of a licensed tradesman in the field involved.
See Qualifications (page 7).
DO NOT USE THIS APPLIANCE IF ANY PART HAS BEEN
EXPOSED TO FLOODING OR WATER DAMAGE. Immediately
call a qualified service agency to inspect the appliance and to make
a determination on what steps should be taken next. If the unit is
exposed to the following, do not operate heater until all corrective
steps have been External fire
1. Damage
Firing without water
2.
Light the water heater in accordance with the Lighting and Operation
Instruction label on the water heater and in this manual Lighting the
Water Heater on page 48.
The water heaters covered by this manual are equipped with
an electronic control system, which automatically sequences
the Combustion Blower, pre and post purging of the combustion
chamber, the spark transformer, the 24-volt gas valve, Main Burner
ignition, and flame sensing. The control system will lock out after
three unsuccessful ignition attempts. See Control System Operation
(page 40).
START-UP PREPARATION
Before attempting start up, thoroughly study and familiarize yourself
with the exact Sequence Of Operation (page 57). Ensure the water
heater is properly grounded. Flame sensing requires an adequate
earth ground. If the water heater is not properly grounded it will
cause ignition failure.
Be certain that the water heater is full of water, that air is purged
from the gas and water lines and that there are no leaks in the gas
and water lines. Ensure all inlet water valves are open.

START UP

START UP
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:
Close the water heater drain valve by turning the handle to the
1.
right (clockwise). The drain valve is on the lower front of the
water heater.
Open the cold water supply valve to the water heater.
2.
Note: The cold water supply valve must be left open when the
water heater is in use.
To insure complete filling of the tank, allow air to exit by opening
3.
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.
Check all water piping and connections for leaks. Repair as
4.
needed.

LIGHTING AND OPERATION LABELS

The instruction label below is affixed to the water heaters that are
covered by this manual at the factory and must be followed when
lighting and operating the water heater.
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