14
TABLE 3
INPUT CHECK TIME REQUIRED TO
CONSUME 1 CU. FT. OF GAS
Type of
BTU Per
Approx. Time Required To
Model
Gas
Cu. Ft.
Consume 1 Cu. Ft. of Gas
BT-80
Natural
1050
50.3 sec.
Propane
2500
119.8 sec.
BT-100
Natural
1050
50.3 sec.
Propane
2500
119.8 sec.
Use this formula to “clock” the meter. Be sure that other gas
consuming appliances are not operating during this interval.
3,600 X H = Btu/Hr
T
T = Time in seconds needed to burn one cubic foot of gas.
H = Heating value of gas in Btu’s per cubic foot of gas.
Btu/Hr = Actual heater input rate.
Example: (Using BT-80 heater)
T = 50.3 seconds/ft
3
H = 1,050 Btu/ft
3
(natural gas)
Btu/Hr = ?
3,600 X 1,050 = 75,100 Btu/Hr (22.0 kW)
50.3
Compare the actual input rate to that given on the heater’s rating
plate. In the example, the BT-80’s full input rate should be 75,100
Btu/Hr for natural gas.
VENT SYSTEM
Examine the venting system every 6 months for obstructions and/
or deterioration of vent piping.
RELIEF VALVE
At least once a year the temperature and pressure relief valve should
be checked to ensure that it is in operating condition. (During manual
operation of this valve, avoid any contact with hot water and take
preventive steps for water damage). Lift the lever at the top of the
valve several times until the valve seats properly and operates freely.
WARNING
THE WATER PASSING OUT OF THE VALVE DURING THIS
CHECKING OPERATION MAY BE EXTREMELY HOT. AVOID
CONTACT AND DISCHARGE SAFELY TO PREVENT WATER
DAMAGE.
If the temperature and pressure relief valve on the heater discharges
periodically or continuously, a problem exists. This may be due to
unusually high water temperatures or pressures in the system, or to
a faulty relief valve. Contact your dealer or a qualified service
technician to find the cause of the problem and to correct it. This
may also be due to thermal expansion in a closed water supply
system. Contact the water supplier or local plumbing inspector
on how to correct this situation.
DO NOT PLUG THE
TEMPERATURE AND PRESSURE RELIEF VALVE.
WARNING
SHOULD OVERHEATING OCCUR OR THE GAS SUPPLY FAIL
TO SHUT OFF, TURN OFF THE MANUAL GAS CONTROL VALVE
TO THE APPLIANCE.
HOT WATER ODOR
On occasion, hot water may develop a strong odor. If this occurs drain
the heater completely, flush thoroughly, and refill. If the problem persists,
chlorination of the heater and replacement of the factory installed
magnesium anodes with aluminum anodes may correct the condition.
Occasionally water softener companies recommend removal of
heater anodes for odor reasons.
CAUTION
Unauthorized removal of heater anode(s) will void the warranty.
Replace the anode as necessary to maintain corrosion
protection. For further information contact your dealer.
ANODE ROD INSPECTION
The heater tank is equipped with anode rods to provide corrosion
control. At least once a year the anode rods should be checked to
determine if replacement is necessary. Initially the anode rods are
approximately 7/8" (22mm) in diameter with a 1/8" (3mm) diameter
steel core wire running down the center of the anode material. THE
ANODES SHOULD BE REPLACED when the 1/8" (3mm) diameter
core wire is visible as this means that the anode material has been
expended in the control of corrosion.
NOTE:
Anode rod inspection may need to be made more
frequently in areas subject to acid rain that obtains their water
supply from surface water as the low pH will accelerate anode
activity.
CAUTION:
Close cold water inlet valve serving heater and open
nearby hot water faucet to relieve the pressure in the heater
before attempting to remove anode(s) for inspection.
WINTER PROTECTION
In regions where freezing weather is encountered, all water must
be drained from unit and piping when out of service (water shut off).
Drain valve must be left open until unit is returned to service.
REPLACEMENT PARTS
Replacement parts may be ordered through A. O. Smith dealers,
authorized servicers or distributors. Refer to the Yellow Pages for
where to call or contact the A. O. Smith Water Products Company,
125 Southeast Parkway, Franklin, TN 37068 (1-800-433-2545). For
Canada call or contact A.O. Smith Water Products Company, 768
Erie Street Stratford, ON N5A 6T3 (519-271-5800 x 401, or visit our
website: www.aosmithwaterheaters.com. When ordering parts, be
sure to state the quantity, part number and description of the item
including the complete model and serial number as it appears on
the product. Refer to the parts list for more information.