Install Instructions

6
SHOULD OVERHEATING OCCUR OR THE GAS SUPPLY FAIL
TO SHUT OFF, TURN OFF THE MANUAL GAS CONTROL VALVE
TO THE WATER HEATER.
Heater must be protected from freezing downdrafts during
shutdown periods.
GROUNDING INSTRUCTIONS
This water heater must be grounded in accordance with the
National Electric Code and/or local codes. These must be followed
in all cases.
This water heater must be connected to a grounded metal,
permanent wiring system; or an equipment grounding conductor
must be run with the circuit conductors and connected to the
equipment grounding terminal or lead on the water heater.
CHEMICAL VAPOR CORROSION
WARNING
CORROSION OF THE FLUEWAYS AND VENT SYSTEM MAY
OCCUR IF AIR FOR COMBUSTION CONTAINS CERTAIN
CHEMICAL VAPORS. SUCH CORROSION MAY RESULT IN
FAILURE AND RISK OF ASPHYXIATION.
Spray can propellants, cleaning solvents, refrigerator and air
conditioning refrigerants, swimming pool chemicals, calcium and
sodium chloride (water softener salt), waxes, and process chemicals
are typical compounds which are potentially corrosive. Do not store
products of this sort near the heater. Also, air which is brought in
contact with the heater should not contain any of these chemicals.
If necessary, uncontaminated air should be obtained from remote
or outside sources. The limited warranty is voided when failure of
water heater is due to a corrosive atmosphere. (Refer to the limited
warranty for complete terms and conditions.)
PROPANE GAS MODELS
Water heaters for propane or liqueed petroleum gas (LPG) are
different from natural gas models. A natural gas heater will not
function safely on LP gas and no attempt should be made to
convert a heater from natural to LP gas.
LP gas must be used with great caution. It is highly explosive and
heavier than air. It collects rst in low areas making odor difcult
to detect at nose level. If LP gas is present or even suspected,
do not attempt to nd the cause yourself. Go to a neighbor’s
house, leaving your doors open to ventilate the house, then call
your gas supplier or service agent. Keep area clear until a service
call has been made.
At times you may not be able to smell an LP gas leak. One cause is
odor fade, which is a loss of the chemical odorant that gives LP gas its
distinctive smell. Another cause can be your physical condition, such
as having a cold or diminishing sense of smell with age. For these
reasons, the use of a propane gas detector is recommended.
IF YOU EXPERIENCE AN OUT-OF-GAS SITUATION, DO NOT
TRY TO RELIGHT APPLIANCES YOURSELF. Only trained
LP professionals should conduct the required safety checks in
accordance with industry standards.
HIGH ALTITUDE INSTALLATIONS
WARNING
INSTALLATIONS ABOVE 2000 FEET REQUIRE REPLACEMENT
OF THE BURNER ORIFICE IN ACCORDANCE WITH THE
NATIONAL FUEL GAS CODE (ANSI Z223.1). FOR CANADIAN
INSTALLATIONS CONSULT CANADIAN INSTALLATION CODES
AND CAN/CGA B149. FAILURE TO REPLACE THE ORIFICES
WILL RESULT IN IMPROPER AND INEFFICIENT OPERATION
OF THE APPLIANCE RESULTING IN THE PRODUCTION
OF INCREASED LEVELS OF CARBON MONOXIDE GAS IN
EXCESS OF SAFE LIMITS WHICH COULD RESULT IN SERIOUS
PERSONAL INJURY OR DEATH.
You should contact your gas supplier for any specic changes
which may be required in your area.
As elevation above sea level is increased, there is less oxygen
per cubic foot of gas. Therefore, the heater input rate should be
reduced at high altitudes for satisfactory operation with the reduced
oxygen supply. Failure to make this reduction could result in an
overring of the heater, causing sooting, poor combustion and/or
unsatisfactory heater performance.
U.S. REQUIREMENTS
Ratings specified by manufacturers for most appliances apply
for elevations up to 2000 feet (610m). For elevations above
2000 feet (610m), ratings must be reduced at the rate of 4%
for each 1000 feet (305m) above sea level. For example, if a
heater is rated at 120,000 Btuh (35 Kwh) at sea level, to rate
the heater at 4000 feet (1219m), you subtract 4 (once for each
thousand feet) x .04 (4% input reduction) x 120,000 (original
rating) from the original rating. Therefore, to calculate the
input rating at 4,000 feet (121.9m): 4 x .04 x 120,000=19,200
Btuh (5.6 Kwh), 120,000 (35 Kwh) - 19,200 (5.6Kwh)=100,800
Btuh (29.4 Kwh). At 6000 feet (1829m) the correct input rating
should be 91,200 Btuh (26.7 Kwh).
The input reduction is primarily achieved by reducing the size
of the main burner orice. To do this, the main burner orices
require replacement with orices sized for the particular installation
elevation. Correct orice sizing and parts may be obtained from
A.O. Smith corporation. When ordering, be sure to state the model
number and the altitude of the location where the water heater
is being installed.
Upon completion of derating of the heater, adjustment to the
gas pressure regulator may be required. See CHECKING THE
INPUT section in this manual for inlet and manifold pressure
requirements.
Also due to the input rating reduction required at high altitudes, the
output rating of the appliance is reduced and should be compensated
for in the sizing of the equipment for the application.