SHOULD OVERHEATING OCCUR OR THE GAS SUPPLY FAIL TO SHUT OFF, TURN OFF THE MANUAL GAS CONTROL VALVE TO THE APPLIANCE.
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.)
LIQUID PETROLEUM MODELS
Water heaters for propane or liquefied 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 first in low areas making odor difficult to detect at nose level. If LP gas is present or even suspected, do not attempt to find 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 SECTION
8.1.2OF 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 specific 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 overfiring 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)=100,000 Btuh (29.4 Kwh). At 6000 feet (1829m) the correct input rating should be 91,200 Btuh (26.7 Kwh).
CANADIAN REQUIREMENTS
Appliances with inputs up to and including 400,000 BTU (117.2 Kw) must be factory equipped with orifices for operation at specific elevations. Standard (sea level) orifices permit operation up to 2000’ (610m) elevation. For operation between 2000’ (610m) and 4500’ (1370m) specify “HIGH ALTITUDE OPERATION” when ordering the heater(s). For operation above 4500’ (2370m) consult factory before ordering.
Field conversion for operation at altitudes other than that specified on the heater rating plate is not permitted.
The input reduction is primarily achieved by reducing the size of the main burner orifice. To do this, the main burner orifices require replacement with orifices sized for the particular installation elevation. Correct orifice sizing and parts may be obtained from A.O. Smith Water Products Company. 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.
