Periodic Maintenance; Venting System Inspection; Draining And Flushing - A.O. Smith 100 Series Installation And Operating Manual

Table 21. Maintenance Schedule
Component Operation
Tank Drain and Flush
Lime Scale Re-
moval
Tank
(Water Less Than
25 Grains Hard)
Lime Scale Re-
moval
Tank (Water Greater
Than 25 Grains
Hard)
Burner
Inspection
Flames
Inspection/Clean-
Burner
ing
Moving Parts Lubrication
Powered Inspection/Clean-
Anodes ing
T&P Valve Test Operation
Vent System Inspection
Condensate
Inspection
Neutralization
Condensate
Cleaning
Collection

VENTING SYSTEM INSPECTION

WARNING
Breathing Hazard - Carbon Monoxide Gas
• Flue gases may escape if vent pipe is not properly
connected.
• Be alert for obstructed, sooted or deteriorated vent
system to avoid serious injury or death.
• Do not store corrosive chemicals in vicinity of water
heater.
• Chemical corrosion of flue and vent system can
cause serious injury or death.
• Analyze the entire vent system to make sure that
condensate will not become trapped in a section of
vent pipe and therefore reduce the open cross
sectional area of the vent.
Breathing carbon monoxide can cause brain damage or death.
Always read and understand instruction manual.
At least once a year a visual inspection should be made of the venting
system. You should:
• Check for obstructions and/or deterioration of the intake air
and/or vent piping and the intake air and vent terminations.
The combustion and ventilation air flow must not be obstructed.
Repair and/or replace immediately as necessary.
Note: Do not reach inside the vent termination while the heater is
in operation.
• Remove any debris that may have accumulated on the screen
in the vent terminations.
• Check all vent system connections for damage or deterioration
which could cause improper venting or leakage of combustion
products. Repair or reseal as necessary.
Be sure the vent piping is properly connected to prevent escape
of dangerous flue gasses which could cause deadly asphyxiation.
Obstructions and deteriorated vent systems may present serious
health risk or asphyxiation.
Chemical vapour corrosion of the flue and vent system may occur
if air for combustion contains certain chemical vapours. Spray

PERIODIC MAINTENANCE

PERIODIC MAINTENANCE
Interval Reference
Every 6
See Draining and Flushing.
Months
Not Required N/A
Annually See Lime Scale Removal.
See Burner Operation And
Every 3
Months Inspection (page 45).
Contact qualified agency or
As Needed
professional.
Not Required N/A
See Anode Rod Maintenance
Annually
(page 46).
See Temperature-Pressure Relief
Semi Annually
Valve Test (page 46).
Annually See Venting System Inspection.
See manual for the conden-
Annually
sate neutralization kit.
Annually See Venting System Inspection.
can propellants, cleaning solvents, refrigerator and air conditioner
refrigerants, swimming pool chemicals, calcium and sodium chloride,
waxes, bleach and process chemicals are typical compounds which
are potentially corrosive.
If after inspection of the vent system you found sooting or
deterioration, something is wrong. Call the local gas utility to correct
the problem and clean or replace the flue and venting before
resuming operation of the water heater.

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 and Figure 2 (page 8) for the location of the water
heater components described below.
DANGER
HOT
HOT
BURN
TO DRAIN THE WATER HEATER STORAGE TANK:
1. Unplug the water heater from the electrical supply.
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. See
Figure 1 (page 8).
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.
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:
1. Unplug the water heater from the electrical supply.
2. Ensure the cold water inlet valve is open.
3. Open a nearby hot water faucet and let the water run until the
water is no longer hot. Then close the hot water faucet.
4. Connect a hose to the drain valve and terminate it to an adequate
drain.
5. 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.
44
• Burn hazard.
• Hot water discharge.
• Keep hands clear of drain
valve discharge.