Draining And Flushing; To Drain The Water Heater Storage Tank; To Flush The Water Heater Storage Tank; Service - A.O. Smith Gas Models Instruction Manual

fIGure 37.
When checking the temperature-pressure relief valve operation,
make sure that (1) no one is in front of or around the outlet of the
temperature-pressure relief valve discharge line, and (2) that the
water discharge will not cause any property damage, as the water
may be extremely hot, see Figure 37.
If after manually operating the valve, it fails to completely reset and
continues to release water, immediately close the cold water inlet
to the water heater, follow the draining instructions, and replace the
temperature-pressure relief valve with a new one.
If the temperature-pressure relief valve on the appliance weeps or
discharges periodically, this may be due to thermal expansion. You
may have a check valve installed in the water line or a water meter
with a check valve. Consult your local water supplier or a qualified
service agency for further information. Do not plug the temperature-
pressure relief valve.

draInInG and flushInG

It is recommended that the water heater storage tank be drained and
flushed every 6 months to reduce sediment buildup. The water heater
should be drained if being shut down during freezing temperatures.
See Figure 1, Features And Components in this manual for the
location of the water heater components described below.

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 Shutoff valve if
the water heater is going to be shut down for an extended
period.
3. Ensure the cold water inlet valve is open.
4. Open a nearby hot water faucet and let the water run until the
water is no longer hot.
5. Close the cold water inlet valve to the water heater.
Burn harzard.
Hot water discharge.
Keep hands clear of drain
valve discharge.
6. Connect a hose to the water heater drain valve and terminate it
to an adequate drain.
7. Open the water heater drain valve and allow all the water to
drain from the storage tank.
8. Close the water heater drain valve when all water in the storage
tank has drained.
9. Close the hot water faucet opened in Step 4.
10. If the water heater is going to be shut down for an extended
period, the drain valve should be left open.

to flush the water heater storaGe tanK:

11. Turn off the electrical supply to the water heater.
12. Ensure the cold water inlet valve is open.
13. Open a nearby hot water faucet and let the water run until the
water is no longer hot. Then close the hot water faucet.
14. Connect a hose to the drain valve and terminate it to an
adequate drain.
15. Ensure the drain hose is secured before and during the entire
flushing procedure. Flushing is performed with system water
pressure applied to the water heater.
16. Open the water heater drain valve to flush the storage tank.
17. Flush the water heater storage tank to remove sediment and
allow the water to flow until it runs clean.
18. Close the water heater drain valve when flushing is completed.
19. Remove the drain hose.
20. Fill the water heater - see Filling The Water Heater in this
manual.
21. Turn on the electrical supply to place the water heater back in
operation.
22. Allow the water heater to complete several heating cycles to
ensure it is operating properly.

servIce

If a condition persists or you are uncertain about the operation of
the water heater contact a qualified service agency.
Use this guide to check a "Leaking" water heater. Many suspected
"Leakers" are not leaking tanks. Often the source of the water can
be found and corrected.
If you are not thoroughly familiar with gas codes, your water heater,
and safety practices, contact your gas supplier or qualified installer
to check the water heater.
Read this manual first. Then before checking the water heater
make sure the gas supply has been turned "OFF", and never turn
the gas "ON" before the tank is completely full of water.
47