A.O. Smith 315456-002 Water Heater User Manual


 
23
Good venting is essential for a gas fired water heater
to operate properly as well as to carry away products of
combustion and water vapor.
It is always recommended that a suitable metal drain pan
be installed under the water heater to protect the area
from water damage resulting from normal condensation
production, a leaking tank or piping connections. Refer to
the “Location Requirements” section.
Water Heater Sounds
During the normal operation of the water heater, sounds or
noises may be heard. These noises are common and may
result from the following:
1. Normal expansion and contraction of metal parts
during periods of heat-up and cool-down.
2. Condensation causes sizzling and popping within the
burner area and should be considered normal.
3. Sediment buildup in the tank bottom will create varying
amounts of noise and may cause premature tank
failure. Drain and flush the tank as directed under the
“Draining and Flushing” section.
Smoke/Odor
The water heater may give off a small amount of smoke
and odor during the initial start-up of the unit. This is due
to the burning off of oil from metal parts of a new unit and
will disappear after a brief period of operation.
Safety Shut-off
This water heater is designed to automatically shut-off in
the event of the following:
1. The burner flame is extinguished for any reason.
2. The water temperature exceeds 195°F (91°C).
3. Excessive build up of dust on the louvers of the air
intake chamber. See Maintenance of your Water
Heater Section.
This unit is also equipped with a flammable vapor sensor
(FV Sensor), designed to shut off the gas supply in the
event the water heater has been exposed to flammable
vapors (e.g., spilled gasoline).
A high temperature limit switch or ECO (Energy Cut Off) in
the tank is used to shut off the unit if the water temperature
exceeds 195°F (91°C). The ECO is a single-use switch,
which, if activated, requires complete replacement of the
entire gas control valve/thermostat. If the ECO should
activate, the water heater cannot be used until the gas
control valve/thermostat is replaced by a qualified technician.
Contact your local dealer for service information.
losses and may satisfy your normal hot water needs. If hot
water use is expected to be more than normal, a higher
thermostat setting may be required to meet the increased
demand. When leaving your home for extended periods
(vacations, etc.) Set the electronic control display tem-
perature “COOLER” button to its lowest setting. This
will maintain the water at low temperatures with minimum
energy losses and prevent the tank from freezing during
cold weather.
FIGURE 21.
Operational Conditions
Condensation
Whenever the water heater is filled with cold water, some
condensate will form while the burner is on. A water
heater may appear to be leaking when in fact the water is
condensation. This usually happens when:
a. A new water heater is filled with cold water for the first
time.
b. Burning gas produces water vapor in water heaters, par-
ticularly high efficiency models where flue temperatures
are lower.
c. Large amounts of hot water are used in a short time and
the refill water in the tank is very cold.
Moisture from the products of combustion condense on the
cooler tank surfaces and form drops of water which may fall
onto the burner or other hot surfaces to produce a “sizzling”
or “frying” noise.
Excessive condensation can cause burner flame problems
due to water running down the flue tube onto the main
burner.
Because of the suddenness and amount of water,
condensation water may be diagnosed as a “tank leak”.
After the water in the tank warms up (about 1-2 hours), the
condition should disappear.
Do not assume the water heater is leaking until there has
been enough time for the water in the tank to warm up.
An undersized water heater will cause more condensation.
The water heater must be sized properly to meet the
family’s demands for hot water including dishwashers,
washing machines and shower heads.
Excessive condensation may be noticed during the
winter and early spring months when incoming water
temperatures are at their lowest.
Gas Control Valve/Thermostat Settings
COOLER
HOTTER
Electronic Control Display