Maintenance; General; Anode Inspection And Replacement; Temperature-Pressure Relief Valve Operation - A.O. Smith DSE-5 Instruction Manual

General

Water heater maintenance includes inspection and testing of the
Temperature Pressure Relief Valve, periodic tank flushing and
cleaning, and removal of lime scale from the heating elements. Where
used, water heating system circulating pumps should be oiled.
Tank flushing and circulating pump lubrication should be performed
in accordance with the maintenance schedule, see Table 7. Tank
sediment removal and element lime scale removal must be performed
when needed as determined by periodic inspections.

anode InspectIon and replaceMent

This water heater is equipped with a non sacrificial powered anode
rod and a sacrificial anode. Sacrificial anodes protect the glass lined
tank from corrosion by sacrificing themselves through electrolysis.
When the anode material is consumed, there is no more protection
and corrosion of the tank accelerates. Powered anode rods are non
sacrificial and should not need to be replaced unless damaged.
Inspection of the sacrificial anode every 6 to 12 months allows you to
identify a spent anode and replace it. Replace the anode when its diameter
is 3/8" (1 cm) of an inch, or annually which ever is first. Aggressive, very
hot and softened water causes rapid consumption of the anode requiring
frequent inspections. Call the toll free number on the back cover of this
manual for information on obtaining replacement anode rods.

teMperature-pressure relIef ValVe operatIon

The teMperature-pressure relIef ValVe must be
manually operated at least once a month. Lift the lever at the top
of valve several times until the valve seats properly and operates
freely, see Figure 2B.
When checking the temperature-pressure relief valve operation,
make sure that (1) no one is in front of or around the outlet of
the temperature-pressure relief valve discharge line, and (2) that
the water discharge will not cause any property damage, as the
water may be extremely hot. Use care when operating valve as
the valve may be hot.
fIGure 6.

MaIntenance

If after manually operating the valve, it fails to completely reset and
continues to release water, immediately close the cold water inlet
to the water heater, follow the draining instructions in the Start Up
section of this manual, and replace the temperature-pressure relief
valve with a properly rated/sized new one.
If the temperature-pressure relief valve on the appliance weeps
or discharges periodically, this may be due to thermal expansion.
Consult your local water supplier or a Qualified Service Agency
for further information. do not pluG the teMperature-
pressure relIef ValVe.
Component
Tank
Elements
taBle 7. MaIntenance schedule.

flushInG

The water heater drain valve should be opened periodically to help
prevent sediment buildup on the tank bottom.
1. Turn off the electrical disconnect switch.
2. Open a nearby hot water faucet until the water is no longer hot,
then close the hot water faucet.
3. Attach hose to outlet opening of drain valve and direct end to drain.
• Open the drain valve by turning the hand wheel to the left
(counterclockwise). Allow water to flow until it runs clean.
• If water does not flow from opened drain valve, follow
instructions for sediment removal.
4. When finished flushing:
• Close heater drain valve and remove hose.
• Turn on electricity.

sedIMent reMoVal

Water borne impurities consist of 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 and cause their failure.
For convenience, sediment removal and element lime scale removal
should be performed at the same time as follows.

lIMe scale reMoVal

Lime scale accumulations on the heating elements is a normal
condition, common to all immersion type elements. Factors which
affect the amounts of this formation are:
1. Amount of hot water used. As the volume of the water heated
increases, more scale results.
2. Water temperature. As the temperature of the water is increased,
more scale is deposited on the elements.
30
Operation Interval
Flushing Monthly
Sediment
As Needed
Removal
Lime Scale
As Needed
Removal
Required
UN-LIME
delimer and
element gaskets