Periodic Maintenance; Venting System Inspection; Anode Rod Inspection; Temperature-Pressure Relief Valve Operation - A.O. Smith Gas Models Instruction Manual

ventInG sYsteM InspectIon

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.

anode rod InspectIon

Each water heater contains at least one anode rod, which will slowly
deplete (due to electrolysis) prolonging the life of the water heater
by protecting the glass-lined tank from corrosion. Adverse water
quality, hotter water temperatures, high hot water usage, hydronic
heating devices, and water softening methods can increase the
rate of anode rod depletion. Once the anode rod is depleted, the
tank will start to corrode, eventually developing a leak.

perIodIc MaIntenance

Certain water conditions will cause a reaction between the anode rod
and the water. The most common complaint associated with the anode
rod is a "rotten egg smell" produced from the presence of hydrogen
sulfide gas dissolved in the water. IMPORTANT: Do not remove this
rod permanently as it will void any warranties. A special anode rod may
be available if water odor or discoloration occurs. NOTE: This rod may
reduce but not eliminate water odor problems. The water supply system
may require special filtration equipment from a water conditioning
company to successfully eliminate all water odor problems.
Artificially softened water is exceedingly corrosive because the
process substitutes sodium ions for magnesium and calcium ions.
The use of a water softener may decrease the life of the water
heater tank.
The anode rod should be removed from the water heater tank every
3 years for inspection. NOTE: artificially softened water requires the
anode rod to be inspected annually.
The following are typical (but not all) signs of a depleted anode rod:
* The majority of the rods diameter is less than 3/8".
* Significant sections of the support wire (approx. 1/3 or more of
theanode rod's length) are visible.
If the anode rod show signs of either or both it should be replaced.
NOTE: Whether re-installing or replacing the anode rod, check for
any leaks and immediately correct if found.
In replacing the anode:
1. Turn off gas supply to the water heater.
2. Shut off the water supply and open a nearby hot water faucet to
depressurize the water tank.
3. Drain approximately 5 gallons of water from tank (Refer to "Draining
and Flushing" for proper procedures). Close drain valve.
4. Remove old anode rod.
5. Use Teflon® tape or approved pipe sealant on threads and install
new anode rod.
6. Turn on water supply and open nearby hot water faucet to purge air
from water system. Check for any leaks and immediately correct
any if found.
Restart the water heater as directed under "Operating Your Water
Heater." See the Repair Parts Illustration for anode rod location.
teMperature-pressure
relIef valve operatIon
46
fIGure 36.