Draining And Flushing; To Drain The Water Heater Storage Tank; To Flush The Water Heater Storage Tank - A.O. Smith 300 Series Installation And Operating Manual

DRAINING AND FLUSHING

Periodic draining and cleaning of sediment from the tank
maybe necessary. It is recommended that the tank be
drained and flushed every 6 months to remove sediment
which may build up during operation. The water heater
should be drained if being shut down during freezing
temperatures. See "Typical Installation" section in this
manual for location of the water heater components
described below.
DANGER
HOT
HOT
BURN

To Drain The Water Heater Storage Tank

1. Turn "OFF" the electrical supply to the water heater.
2. Turn "OFF" the gas supply at the Main Gas shut-off
Valve.
3. Open a hot water faucet and let the hot water run until
it is cool (This may take 10 minutes or longer).
Warning: Be sure the water runs cool before draining the
tank to reduce the risk of scalding.
4. Connect a garden hose to the drain valve and place
the other end of the hose in an adequate drain,
outside, or in buckets. Note that sediment in the bottom
of the tank may clog the valve and prevent it from
draining. If you can't get the tank to drain, contact a
qualified person.
5. CLOSE the cold-water inlet valve to the water heater.
6. Open the drain valve on the water heater.
7. If not already done, open a hot water faucet to help
the water in the tank drain faster.
8. If a large amount of sediment was present when
the tank was drained, follow instructions in the
"To Flush The Water Heater Storage Tank" section.
9. Close the water heater drain valve when all water in
the storage tank has drained and remove the hose.
10. Follow instructions in the "Filling The Water Heater"
section.
11. Follow the lighting instructions on the label or see
"Lighting Instructions" to restart the water heater.
Note: If the water heater is going to remain shut down and
empty for an extended period, the drain valve should be
left open with hose connected allowing water to terminate
to an adequate drain.
50
• Burn hazard.
• Hot water discharge.
• Keep hands clear of drain
valve discharge.
www.hotwater .com

To Flush The Water Heater Storage Tank

Follow Step 1 through Step 7 in the
"To Drain The Water Heater Storage Tank" section.
1. Flush the tank by opening the cold water supply valve
and letting the water run until no more sediment drains
from the tank.
2. Close the water heater drain valve when flushing is
completed and remove the drain hose.
3. Ensure the heater is full of water.
4. Follow instructions in the "Filling The Water Heater"
section.
5. Follow the lighting instructions on the label or see
"Lighting Instructions" to restart the water heater.
Caution: Do not turn on power to the water heater unless
the tank is full. Open a hot-water faucet and allow the
water to run until the air is purged and the water flows
uninterrupted from the faucet.
Important: When operating a cold tank, condensation can
occur and drip on the burner. This should not be confused
with a tank leak.
100304526_2000545240 _Rev. 01