A.O. Smith HYB-90N, Installation And Operating Manual

Page: 14 / 112

14 www.hotwater.com 316888-001 Rev. 00 dRaFt Jun 28 245
COMBUSTION AIR AND VENTILATION
A gas water heater cannot operate properly without the
correct amount of air for combustion. Do not install in
a con
fi ned area such as a closet, unless you provide
adequate air supply. Never obstruct the fl ow 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
fi re or explosion and cause
death, serious bodily injury, or property damage.
FIGURE 10
If this water heater will be used in beauty shops, barber
shops, cleaning establishments, or self-service laundries
with dry cleaning equipment, it is imperative that the water
heater(s) be installed so that all air for combustion and
ventilation is taken from outdoors.
Propellants of aerosol sprays and volatile compounds,
(cleaners, chlorine based chemicals, refrigerants, etc.) in
addition to being highly
fl ammable in many cases, will also
react to form corrosive hydrochloric acid when exposed to
the combustion products of the water heater. The results
can be hazardous, and also cause product failure.
APPLIANCES IN ENCLOSURES
If the water heater is installed in an enclosure ensure an
air supply is provided as required by the current edition
of CAN/CSA-B149.1, the Natural Gas and Propane
Installation Code.
CHEMICAL VAPOUR CORROSION
CORROSION OF THE FLUEWAYS AND VENT
SYSTEM MAY OCCUR IF AIR FOR COMBUSTION
CONTAINS CERTAIN CHEMICAL VAPOURS. SUCH
CORROSION MAY RESULT IN FAILURE AND RISK OF
ASPHYXIATION.
Spray can propellants, cleaning solvents, refrigerator and
air conditioning refrigerants, swimming pool chemicals,
calcium and sodium chloride (water softener salt), waxes,
and process chemicals are typical compounds which are
potentially corrosive.
Do not store products of this sort near the heater. Also, air
which is brought in contact with the heater should not contain
any of these chemicals. If necessary, uncontaminated air
should be obtained from remote or outside sources. The
limited warranty is voided when failure of water heater is
due to a corrosive atmosphere. (See limited warranty for
complete terms and conditions).
WATER PIPING
NOTE: Refer to “HOT WATER CAN SCALD” in the “Water
Piping - Mixing Valve” section of this manual.
This water heater should not be connected to any heating
systems or component(s) used with a non-potable water
heating appliance.
All piping components connected to this unit should be
suitable for use with potable water.
Toxic chemicals, such as those used for boiler treatment
should not be introduced into this system.
When the system requires water for space heating at
temperatures higher than required for domestic water
purposes, a mixing valve must be installed. Please refer
to Figure 3 for suggested piping arrangement.