Lochinvar Commercial Electric Water Heaters - Manual (Page 15)

Scale accumulation in the bottom of the storage tank may
be removed by turning off main power and draining the
tank. Once all water is removed, the hand hole access can be
removed. This will allow large accumulations of scale to be
cleaned from the bottom of the tank.
15
Corrosion due to water chemistry generally shows up first
in the hot water system because heated water increases the
rate of corrosive chemical reactions.
Water heater maintenance includes periodic tank flushing
and cleaning and removal of lime scale from the heating
elements. Where used, the water heating system circulating
pump should be oiled.
FLUSHING THE STORAGE TANK
1. Turn off main power at the electrical disconnect switch.
2. Open the drain valve. Allow water to flow until it runs
clean.
3. Close the drain valve when finished flushing.
4. Open a hot water faucet closest to the water heater and
the water to run to insure that no air was drawn into
the tank during the flushing process. Close the faucet
when the water runs clear with no discharge of air.
5. Turn on main power the electrical disconnect switch
(after filling).
SEDIMENT REMOVAL
Water born impurities consist of dissolved minerals which
precipitate out of the heated water and fine particles of soil
and sand which settle out and form a layer of sediment on
the bottom of the tank. In time, if not removed, the level of
sediment might reach the heating elements.
For convenience, sediment removal and element lime scale
removal should be performed at the same time. Proceed
with the following instructions:
Sediment and Lime Scale Removal
Sediment and lime scale accumulation on the heating
elements is a normal condition common to all immersion
type elements. Factors which affect the amount of this
formation are:
1. Amount of hot water used. As the volume of water
increases, more scale results.
2. Water temperature. As the temperature of the water is
increased, more scale is deposited on the elements.
3. Characteristics of water supply. Regardless of water
treatment, the elements should be examined regularly.
NOTE:
All gaskets on disassembled clean-out openings
must be replaced with new gaskets on
re-assembly. Gaskets are available from your
distributor.
Water scale accumulations on the immersion heating
element reduce the ability of the elements to heat water and
may cause noise to occur during operation. It is
recommended that a heating element be removed at least
once a year for examination. If it is scaled, all of the
elements should be removed and cleaned. The element
gasket must be replaced when the element is removed for
cleaning.
Small accumulations of lime scale may be removed with a
stiff bristle brush. Severe accumulations of lime scale
should be removed by dissolving the accumulation in a
commercial delimer. Do not use muratic or hydrochloric
acid base deliming solutions to remove lime scale from the
elements. Do not pour delimer into tank. Deliming
solutions may damage the glass lined interior of the tank.
ƽ DANGER
Keep all delimers away from anode rods to prevent
the formation of flammable and explosive gas.
1. Drain the heater following "SHUTDOWN
PROCEDURE" instructions.
2. Disconnect the wires attached to the element terminals.
Try not to disturb the wiring unnecessarily and
reconnection will be easier.
3. Loosen the screw-in element flange with a socket and
breaker bar. Do not use an impact gun (air or electric) to
remove the element flanges from the tank. Mark the
location of each element in the tank openings so they
may be returned to their original position.
4. Remove the elements from the opening with a twisting,
pulling action if the elements are scaled beyond the size
of the tank flange openings. Brush loose scale from
elements.
5. Place scaled ends of heating elements into a deliming
solution and allow scale to dissolve. Do not permit the
delimer or water to contact heating element electrical
terminals.
6. Flush clean ends of elements with water when deliming
or cleaning is completed.