Unit installation

32
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 the anode(s) will void the warranty. 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.
For models with top inlet and outlet, it is recommended that,
before removing the inner cover for cleaning, inspection or
removal of inner parts, you obtain two new nipple collars, part no.
74060. The nipple collars on the heater will usually be damaged
when removed. New pipe collars will insure that the seal is such
as to prevent leakage of flue products when properly installed.
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.
RECOMMENDED PROCEDURE FOR
PERIODIC REMOVAL OF LIME DEPOSITS
FROM TANK TYPE COMMERCIAL WATER
HEATERS
The amount of calcium carbonate (lime) released from water is
in direct proportion to water temperature and usage, see chart.
The higher the water temperature or water usage, the more lime
deposits are dropped out of the water. This is the lime scale
which forms in pipes, heaters and on cooking utensils.
Lime accumulation not only reduces the life of the equipment but
also reduces efficiency of the heater and increases fuel
consumption.
The usage of water softening equipment greatly reduces the
hardness of the water. However, this equipment does not always
remove all of the hardness (lime). For this reason it is
recommended that a regular schedule for deliming be
maintained.
The time between cleaning will vary from weeks to months
depending upon water conditions and usage.
Refer to A. O. Smith booklet, Form No. 4800, entitled “Why? When
and How” for detailed description on tank inspection and
cleanout. UN•LIME
®
and the booklet may be obtained through
your A. O. Smith dealer or distributor.
FIGURE 23
DELIMING SOLVENTS
A. O. Smith recommends the use of UN•LIME for deliming.
UN•LIME is a patented food grade acid which is safe to handle
and does not create the harmful fumes which are associated
with other products.
UN•LIME may be obtained from your dealer, distributor or the A.
O. Smith Product Service Division. Order Part Number 4763, 1
gallon (3.8 L), packed 4 gallons (15.2 L) per case or Part Number
4813, 5 gallon (18.9 L) container.
NOTE: Un•Lime is not available for use in Canada
Hydrochloric base acids are not recommended for use on glass
lined tanks.
CAUTION
Observe handling instructions on label of product being used.
TANK CLEANOUT PROCEDURE
The following practices will ensure longer life and enable the
unit to operate at its designed efficiency:
1. Once a month the heater should be flushed. Open the drain
valve and allow two gallons of water to drain from the heater.
Inlet water valve should remain open to maintain pressure in
tank.
2. A cleanout opening is provided for periodic cleaning of the
tank. Gas must be shut off and heater drained before opening
cleanout.