A.O. Smith FDVT Water Heater User Manual


 
21
be called to determine the reason for limit operation and thus
avoid repeated thermostat replacement. Lower the temperature
adjustment dial setting on the new control.
VENTING
HAVE VENTING SYSTEM CHECKED EVERY SIX MONTHS FOR
OBSTRUCTIONS AND/OR DETERIORATION IN VENT PIPING.
TEMPERATURE & PRESSURE RELIEF VALVE
At least once a year, the temperature and pressure relief valve,
fig. 1. must 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 water does not flow, remove the valve and inspect for
obstructions or corrosion. Have a qualified servicer replace
with a new valve of the recommended size as necessary. Do
not attempt to repair the valve, as this could result in improper
operation and a tank explosion. In areas with poor water
conditions, it may be necessary to inspect the T&P valve more
frequently.
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.
DRAINING
If the heater is to be shut off and exposed to freezing
temperatures, it must be drained. Water, if left in the tank and
allowed to freeze, will damage the heater.
Turn off the gas and cold water inlet valve to the heater, fig. 1.
Open a nearby hot water faucet and the heater drain valve.
BE CAREFUL TO GRASP THE DRAIN VALVE HANDLE SO
THAT THE HAND IS NOT EXPOSED TO HOT WATER. IF
DESIRED, A HOSE MAY BE CONNECTED TO THE DRAIN
VALVE TO CARRY THE WATER AWAY.
DANGER
The water CAN BE HOT.
The drain valve must be left open during the shutdown
period.
To restart heater, refer to the FILLING instructions under
OPERATION.
Periodically open the drain valve and allow the water to run until
it flows clean. This will help prevent sediment build-up in the
tank.
It is normal for lime and scale deposits to form within the tank.
Such deposits will not be removed by periodic draining. It is
necessary to chemically delime the affected parts in water
areas where such deposits are encountered. Contact your
dealer or plumber for deliming information.
CONDENSATION
Combustion products contain water vapor which can
condense on the cooler surfaces of the tank forming droplets
which drip into the fire or run out on the floor. This is common
at the time of startup, after installation, during periods of time
when incoming water is very cold, or the heater may be
undersized for the requirements.
Occasional or steady water leakage from the bottom of the flue
may be caused by corrosive combustion products or an
improper vent. Check with your dealer for more information.
CATHODIC PROTECTION - ANODE
The anode rod within the tank is designed to be slowly
consumed cathodically, minimizing corrosion in the glass-
lined tank. A hydrogen sulfide (rotten egg) odor may result if
water contains high sulfate and/or minerals. Chlorinating the
water supply should minimize the problem. (See EXTENDED
NON-USE PERIODS).
NOTE: Anode must remain installed (except for inspection) to
avoid shortening tank life. See LIMITED WARRANTY. Replace as
necessary.
ANODE ROD MAINTENANCE
The anode rod is used to protect the tank from corrosion. Most
hot water tanks are equipped with an anode rod. The
submerged rod sacrifices itself to protect the tank. Instead of
corroding the tank, water ions attack and eat away the anode
rod. This does not affect the water’s taste or color. The rod
must be maintained to keep the tank in operating condition.
Anode deterioration depends on water conductivity, not
necessarily water condition. A corroded or pitted anode rod
indicates high water conductivity and should be checked and/
or replaced more often than an anode rod that appears to be
intact. Replacement of a depleted anode rod can extend the
life of your water heater. Inspection should be conducted by a
qualified technician, and at a minimum should be checked
annually after the warranty period.
CAUTION
Before removing the anode: 1) the tank water should be cool, 2)
the cold water shut off valve must be closed, and 3) water
pressure must be relieved by opening a nearby faucet.