Combustion Air And Ventilation; Corrosion And Water Quality - A.O. Smith 100 Series Installation And Operating Manual

Fire and Explosion Hazard
Read the instruction manual before
installing, using, or servicing the water
heater.
•
Improper use can result in fire or
explosion.
•
Maintain required clearances to
combustibles.
Minimum clearances from combustible materials are stated on
the data plate located on the front of the water heater. Standard
clearances are 0 mm (0") at the sides and rear, 0 mm (0") from the
front, and 0 mm (0") from the top. If the clearances from combustible
material stated on the water heater differ from the standard
clearances, install the water heater according to the clearances
stated on the water heater.
Adequate clearance for inspection and service should be considered
before installation. A minimum of 610 mm (24") of front clearance
and 102 mm (4") on each side should be provided for access to
replaceable and/or serviceable parts such as drain valve, condensate
drain, temperature-pressure relief valve, and the vent connection
(exhaust elbow).
Figure 9 may be used as a reference guide to locate the specific
clearance locations. When installing the water heater, consideration
must be given to proper location. The location selected should be
as close to the wall as practicable and as centralized with the water
piping system as possible.
CEILING
0 mm
WITHOUT DOOR
(0") MIN.
LEFT RIGHT
WALL WALL
FRONT VIEW
*For service access
Figure 9. Clearance Locations

COMBUSTION AIR AND VENTILATION

A gas water heater cannot operate properly without the correct
amount of air for combustion. Never obstruct the flow of ventilation
air. If you have any doubts or questions at all, call your gas supplier.
Failure to provide the proper amount of combustion air can result in
a fire or explosion and cause death, serious bodily injury, or property
damage.
TOP VIEW TOP VIEW
OF CLOSET OF CLOSET
WITH DOOR
0mm
(0") MIN.
WATER WATER
HEATER HEATER
*102mm
0mm
(4") MIN.
(0") MIN.
Breathing Hazard - Carbon Monoxide Gas
Breathing carbon monoxide can cause brain damage or death.
Always read and understand instruction manual.
12" max
100 sq in
Propellants of aerosol sprays and volatile compounds, (cleaners,
chlorine based chemicals, refrigerants, etc.) in addition to being
highly flammable in many cases, will also react to form corrosive
acids when exposed to the combustion products of the water heater.
The results can be hazardous, and also cause product failure. Air
for combustion and ventilation must not come from a corrosive
atmosphere. Any failure due to corrosive elements in the atmosphere
is excluded from warranty coverage.
0mm It is imperative that the water heater(s) be installed direct vent so
(0") MIN.
that all air for combustion and ventilation is taken from outdoors.
*610mm
(24") MIN.

CORROSION AND WATER QUALITY

Water quality will vary from location to location and may contain
contaminates that may reduce the life or performance of the water
heater.
Contaminates which can reduce the life or performance of the water
heater if present in high quantities include those which contribute
to hardness (dissolved minerals such as sodium, calcium and
magnesium); plus chlorides and sulfates. Additionally, water that is
too acidic or alkaline (measured as pH) can reduce the life of the
water heater. Water treatment systems (such as water softeners for
hardness) should be used and maintained properly if the contaminate
levels exceed the following:
Warranty is void in applications which exceed the water quality
requirements listed below.
Total Hardness
Chloride
pH
Alkalinity
13
WARNING
• Install water heater in accordance with the
instruction manual and B149.1.
• To avoid injury, combustion and ventilation air
must be taken from outdoors.
• Do not place chemical vapour emitting products
near water heater.
Ventilation
Air
Opening
Front View of Closet Door
Figure 10. Closet Door Ventilation
Table 3. Water Quality Requirements
205 mg/liter (12 grains per gal.) max.
200 mg/liter (12 grains per gal.) max.
6.5-8.0
200 mg/liter (12 grains per gal.) max.
Rectangular
3" min.
Air Duct