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 TEMPERATUREAND PRESSURE RELIEF VALVE.
WARNING
SHOULD OVERHEATING OCCUR OR THE GAS SUPPLYFAIL 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.
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