Operational Conditions - A.O. Smith BL-80 Instruction Manual

CHECKING GAS INPUT
With this heater in operation, determine whether it is receiving the
full rated input of gas. This may be done by timing the gas meter
and measuring gas pressure with a gauge or manometer. When the
heater is operating at full capacity (full gas input) it should consume
approximately 1 cubic foot of gas in the time shown in Table 5.
TABLE 5. INPUT CHECK TIME REQUIRED
TO CONSUME 1 CU. FT. OF GAS
Model Type of Gas
BL-80
Natural
BL-100
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:
T = 50.3 seconds/ft
3
H = 1,050 Btu/ft (natural gas)
3
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 BL-100's full input rate should be 75,100
Btu/Hr for natural gas.
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.
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.
SMOKE/ODOR
It is not uncommon to experience a small amount of smoke and odor
during the initial start-up. This is due to burning off of oil from metal
parts, and will disappear in a short while.
STRANGE SOUNDS
Possible noises due to expansion and contraction of some metal
parts during periods of heat-up and cool-down do not necessarily
represent harmful or dangerous conditions.
Condensation causes sizzling and popping within the burner area
during heating and cooling periods and should be considered normal.
See "Condensation" in this section.
BTU Per Approx. Time Required To
Cu. Ft. Consume 1 Cu. Ft. of Gas
1050 50.3 sec.

OPERATIONAL CONDITIONS

SMELLY WATER
In each water heater there is installed at least one anode rod for
corrosion protection of the tank. Certain water conditions will cause a
reaction between this rod and the water. The most common complaint
associated with the anode rod is one of a "rotten egg smell" in the
hot water. This odor is derived from hydrogen sulfide gas dissolved
in the water. The smell is the result of four factors which must all be
present for the odor to develop:
a. A concentration of sulfate in the supply water.
b. Little or no dissolved oxygen in the water.
c. A sulfate reducing bacteria which has accumulated within the
water heater (this harmless bacteria is nontoxic to humans).
d. An excess of active hydrogen in the tank. This is caused by the
corrosion protective action of the anode.
Smelly water may be eliminated or reduced in some water heater
models by replacing the anode(s) with one of less active material,
and then chlorinating the water heater tank and all hot water lines.
Contact the local water heater supplier or service technician for
further information concerning an Anode Replacement Kit and
this chlorination treatment.
If the smelly water persists after the anode replacement and chlorination
treatment, we can only suggest that chlorination or aeration of the water
supply be considered to eliminate the water problem.
Do not remove the anode leaving the tank unprotected. By doing
so, all warranty on the water heater tank is voided.
"AIR" IN HOT WATER FAUCETS
HYDROGEN GAS: Hydrogen gas can be produced in a hot
water system that has not been used for a long period of time
(generally two weeks or more). Hydrogen gas is extremely
flammable and explosive. To prevent the possibility of injury
under these conditions, we recommend the hot water faucet,
located farthest away, be opened for several minutes before
any electrical appliances which are connected to the hot water
system are used (such as a dishwasher or washing machine). If
hydrogen gas is present, there will probably be an unusual sound
similar to air escaping through the pipe as the hot water faucet
is opened. There must be no smoking or open flame near the
faucet at the time it is open.
HIGH WATER TEMPERATURE SHUT OFF SYSTEM
This water heater is equipped with an automatic gas Shut-off
system. This system works when high water temperatures are
present. The high temperature Shut-off is built into the gas control
valve. It automatically resets when the temperature at thermostat
level drops below 120 degrees Fahrenheit.
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