22
RELIEF VALVE
At least once a year, the temperature and pressure relief valve
should be checked to ensure that it is in operating condition. Lift
the lever at the top of the valve several times until the valve seats
properly and operates freely.
If the appliance installation includes other relief valves, such as
in “remote” storage tanks etc., check their relief valve operation
with the same frequency.
WARNING
THE WATER PASSING OUT OF THE VALVE DURING THIS
CHECKING OPERATION MAY BE EXTREMELY HOT. AVOID
CONTACT AND DISCHARGE SAFELY TO PREVENT WATER
DAMAGE.
If the temperature and pressure relief valve on the heater
discharges periodically or continuously, a problem exists. This
may be due to unusually high water temperatures or pressures
in the system, or to a faulty relief valve. Contact your dealer or a
qualified service technician to find the cause of the problem and
to correct it. This may also be due to thermal expansion in a
closed water supply system. Contact the water supplier or local
plumbing inspector on how to correct this situation.
DO NOT
PLUG THE TEMPERATURE AND PRESSURE RELIEF VALVE.
WARNING
SHOULD OVERHEATING OCCUR OR THE GAS SUPPLY FAIL TO
SHUT OFF, TURN OFF THE MANUAL GAS CONTROL VALVE TO
THE APPLIANCE.
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" in diameter with a 1/8" diameter
steel core wire running down the center of the anode material.
THE ANODES SHOULD BE REPLACED when the 1/8" 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.
FLUSHING
1. Turn off the heater electrical disconnect switch.
2. Open the drain valve and allow water to flow until it runs clean.
3. Close the drain valve when finished flushing.
4. Turn on the heater electrical disconnect switch.
DRAINING
The heater must be drained if it is to be shut down and exposed
to freezing temperatures. Maintenance and service procedures
may also require draining the heater.
1. Turn off the heater electrical disconnect switch.
2. Close the cold water inlet valve to heater.
3. Open a nearby hot water faucet to vent the system.
4. Open the heater drain valve.
5. If the heater is being drained for an extended shutdown, it is
suggested the drain valve be left open during this period.
• Follow FILLING instructions when restoring hot water
service.
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.
