Troubleshooting - A.O. Smith del and del Installation & Operation Manual

3. Using a flat tip screwdriver, rotate the adjusting knob to the
desired temperature setting.
4. Replace the covers and access panels, and turn on heater
electrical supply.
Valves for reducing point-of-use temperature by mixing cold and
hot water are available (See Figure 5). Also available are
inexpensive devices that attach to faucets to limit hot water
temperatures. Contact a licensed plumber or the local plumbing
authority.
A non-adjustable high temperature limit control operates before
steam temperatures are reached. The high limit is in the same
area as the upper thermostat and must be reset manually when
it operates. BECAUSE THE HIGH LIMIT OPERATES ONLY
WHEN ABNORMALLY HIGH WATER TEMPERATURES ARE
PRESENT, IT IS IMPORTANT THAT A QUALIFIED SERVICE
AGENT BE CONTACTED TO DETERMINE THE REASON FOR
OPERATION BEFORE RESETTING.
FIGURE 5
DRAINING
If the heater is to be shut down and exposed to freezing
temperatures, it must be drained. Water, if left in the tank and
allowed to freeze, will expand and damage the heater.
1. Turn off the electrical switch and cold water inlet valve.
• If desired, a hose may be connected to the drain valve
to carry the water away.
2. Open a nearby hot water faucet and the heater drain
valve.
• Be careful to grasp the drain valve handle in such a
way that the hand will not be exposed to hot water.
3. The drain valve must be left open during the shutdown
period.
• To restart heater, refer to the foregoing FILLING
instructions.
MAINTENANCE
Electric water heater maintenance consists of cleaning the tank
and removing lime (or scale) from the heating elements in hard
water areas. Tank flushing should be performed monthly. Tank
sediment removal and element lime scale removal must be
performed when needed as determined by periodic inspections.
Your dealer should be contacted for element cleaning. In some
instances a hissing sound may be heard as the scale builds up.
This noise is normal.
Once a month the temperature and pressure relief valve should
be checked to ensure that it is in operating condition. Lift the
lever on the valve several times until the valve seats properly and
operates freely.
THE WATER PASSING OUT OF THE VALVE DURING THIS
CHECKING OPERATION MAY BE EXTREMELY HOT.
It is recommended that the drain valve on this unit be opened
once a month and 1 to 2 gallons of water be allowed to drain
out. This will help to prevent sediment buildup in the tank
bottom.
ANODE INSPECTION AND REPLACEMENT
This water heater is equipped with a sacrificial anode rod.
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.
Inspection of the 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. Anodes are available from your distributor or
A.O. Smith.

TROUBLESHOOTING

CHECKLIST
Before contacting your dealer, check the water heater to see if
the apparent malfunction is caused by some external fault.
Consulting this checklist may eliminate the need for a repair call
and restore hot water service.
NOT ENOUGH OR NO HOT WATER
1. Be certain that the water heater electrical switch is turned to
the ON position.
• In some areas an additional special meter, controlled
by a timer, is used to govern the periods electricity is
available. If the heater operates on a timed electrical
circuit, recovery will be limited to certain hours.
2. Check for loose or blown fuses in the water heater circuit.
3. If the water has been excessively hot and is now cold, the high
temperature limit control may have operated. To restore
service, contact your dealer or utility company. Refer to
TEMPERATURE REGULATION section.
4. The storage capacity of the heater may have been exceeded
by large demands of hot water.
5. If the heater was installed when incoming water temperatures
were warm, colder incoming temperatures will create the
effect of less hot water.
8
CAUTION