For Your Information; Start Up Conditions; Operational Conditions; Periodic Maintenance - A.O. Smith 120 Series Instruction Manual

START UP CONDITIONS

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 "Condensate" in this manual.

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. The smell is a 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 water lines. Contact the local
water heater supplier or service agency 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.

VENTING SYSTEM INSPECTION

FOR YOUR INFORMATION

PERIODIC MAINTENANCE

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 SHUTOFF SYSTEM
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 and requires complete
replacement of the entire gas control valve/thermostat. If the
ECO should actuate, the water heater cannot be used until the
gas control valve/thermostat is replaced by a qualified service
agent. Contact the local water heater supplier or service agency
for service information.
At least once a year a visual inspection should be made of the venting
system. You should look for:
1. Obstructions which could cause improper venting. The combustion
and ventilation air flow must not be obstructed.
2. Damage or deterioration which could cause improper venting or
leakage of combustion products.
Be sure the vent piping is properly connected to prevent escape of
dangerous flue gasses which could cause deadly asphyxiation.
Obstructions and deteriorated vent systems may present serious
health risk or asphyxiation.
Chemical vapor corrosion of the flue and vent system may occur
if air for combustion contains certain chemical vapors. Spray can
propellants, cleaning solvents, refrigerator and air conditioner
refrigerants, swimming pool chemicals, calcium and sodium chloride,
waxes, bleach and process chemicals are typical compounds which
are potentially corrosive.
If after inspection of the vent system you found sooting or deterioration,
something is wrong. Call the local gas utility to correct the problem
and clean or replace the flue and venting before resuming operation
of the water heater.
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