A.O. Smith GPVL-50 Service Handbook page 33

CAUSES The chlorination procedure is used to eliminate various bacteria that accumulate and grow in water
heaters. These bacteria often cause odorous or discolored water conditions.
TREATMENT The simplest treatment available is the shock-chlorination of the system. This is a surface treatment,
and often requires repeated trials in heavily infected systems. The chlorination of a system requires
that you follow each step explicitly to avoid an untreated portion of the piping system from re-infecting
another part. Longer lasting solutions include chlorination or aeration of the water supply.
PROCEDURE Please read the steps of the chlorination procedure prior to beginning. If you feel uncomfortable
performing any of these steps, contact a service person to perform this procedure for you.
STEP 1 Turn off the gas and electric supply to the tank.
STEP 2 Turn off the cold water supply valve to the tank.
STEP 3 Open a nearby hot water faucet to relieve the vacuum.
STEP 4 Drain all the water from the tank (a water-hose may be needed).
STEP 5 Remove the anode rod(s), and close the drain valve.
STEP 6 Using a funnel in the anode opening add one gallon of household chlorine bleach for every 25 gallons
of tank capacity.
STEP 7 Reinstall anode rod(s) after inspecting and replacing as needed.
STEP 8 Open cold water supply valve and refi ll the system. Then draw the water to every hot water fi xture,
until the smell of chlorine is detected. Operate dish and clothes washers until a noticeable amount
of the chlorine is detected as well. All hot water lines must receive treatment.
STEP 9 Leave the chlorine solution undisturbed for one hour or more.
STEP 10 After the contact time has elapsed, drain the tank according to steps 2, 3, & 4.
STEP 11 Close the drain valve and refi ll the tank. Allow the tank to sit for 15 minutes. Repeat steps 2, 3, and
4. Continue to fl ush the tank if the water is discolored or contains a chlorine odor.
STEP 12 Close the drain valve and refi ll the tank. Flush all chlorine from the piping by opening every hot water
outlet/ appliance.
STEP 13 Return hot water heating system to service by following the recommended start-up procedure posted
on the unit or in the manual.
CAUSES • The heating capacity of the water heater has been exceeded: complaints regarding an insuffi cient
supply of hot water are typically the result of a water heater that cannot meet the demands of the
residence (both people and appliances). The demand for suffi cient hot water may also be exceeded
if additional people and/or appliances are added to the residence.
• Operating Set Point is too low.
• Mineral build-up.
• Hot water supply valve(s) to fi xtures not fully open.
• Inlet/outlet water piping connections to water heater reversed.
• Dip tube inside water inlet connection missing.
THE FIX Compare hot water requirements with the capacity of the water heater. If necessary, install a water
heater with greater capacity.
• Turn temperature knob to desired temperature as described in the Manual.
• Drain the tank (see "Draining and Flushing" section in the Manual). Determine if water treatment
is needed.
• Check to see if hot water supply valve is fully open, check inlet/outlet piping connections to water
heater are not reversed, check to see if the dip tube inside water inlet connection is not missing.
CHLORINATION PROCEDURE
NOT ENOUGH HOT WATER
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