Contaminated Air; Air Requirements - A.O. Smith BTR 151 Instruction Manual

no valve or other obstruction is to be placed between the
Temperature-Pressure Relief Valve and the tank. Do not connect
discharge piping directly to the drain unless a 6" (15.2 cm)
air gap is provided. To prevent bodily injury, hazard to life, or
property damage, the relief valve must be allowed to discharge
water in adequate quantities should circumstances demand. If
the discharge pipe is not connected to a drain or other suitable
means, the water flow may cause property damage.
CAUTION
Water Damage Hazard
•
Temperature-Pressure Relief Valve discharge
pipe must terminate at adequate drain.
t&p Valve discharge pipe requirements:
• shall not be smaller in size than the outlet pipe size of the
valve, or have any reducing couplings or other restrictions.
• Shall not be plugged or blocked.
• Shall not be exposed to freezing temperatures.
• Shall be of material listed for hot water distribution.
• Shall be installed so as to allow complete drainage of both
the Temperature-Pressure Relief Valve and the discharge
pipe.
• Must terminate a maximum of six inches above a floor
drain or external to the building. In cold climates, it is
recommended that the discharge pipe be terminated at an
adequate drain inside the building.
• Shall not have any valve or other obstruction between the
relief valve and the drain.
The Temperature-Pressure Relief Valve must be manually
operated at least twice a year. Caution should be taken to ensure
that (1) no one is in front of or around the outlet of the Temperature-
Pressure Relief Valve discharge line, and (2) the water manually
discharged will not cause any bodily injury or property damage
because the water may be extremely hot. 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 in this manual, and replace
the Temperature-Pressure Relief Valve with a properly rated/sized
new one.
note: The purpose of a Temperature-Pressure Relief Valve is
to prevent excessive temperatures and pressures in the storage
tank. The T&P valve is not intended for the constant relief of
thermal expansion. A properly sized thermal expansion tank must
be installed on all closed systems to control thermal expansion,
see Closed Water Systems and Thermal Expansion on page 13.
Burn hazard.
Hot water discharge.
Keep clear of Temperature-
Pressure Relief Valve
discharge outlet.
If you do not understand these instructions or have any questions
regarding the Temperature-Pressure Relief Valve call the toll free
number listed on the back cover of this manual for technical
assistance.

contaminated air

Breathing Hazard - Carbon Monoxide Gas
Install water heater in accordance with
the Instruction Manual and NFPA 54 or
CAN/CSA-B149.1.
To avoid injury, combustion and ventilation
air must be taken from outdoors.
Do not place chemical vapor emitting
products near water heater.
Breathing carbon monoxide can cause brain damage or
death. Always read and understand instruction manual.
Corrosion of the flue ways and vent system may occur if air for
combustion contains certain chemical vapors. Such corrosion
may result in failure and risk of asphyxiation.
Combustion air that is contaminated can greatly diminish the life
span of the water heater and water heater components such as
hot surface igniters and burners. Propellants of aerosol sprays,
beauty shop supplies, water softener chemicals and chemicals
used in dry cleaning processes that are present in the combustion,
ventilation or ambient air can cause such damage.
Do not store products of this sort near the water heater. Air which
is brought in contact with the water heater should not contain any
of these chemicals. If necessary, uncontaminated air should be
obtained from remote or outdoor 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).

air reQuirements

Breathing Hazard - Carbon Monoxide Gas
Install water heater in accordance with
the Instruction Manual and NFPA 54 or
CAN/CSA-B149.1.
To avoid injury, combustion and ventilation
air must be taken from outdoors.
Do not place chemical vapor emitting
products near water heater.
Breathing carbon monoxide can cause brain damage or
death. Always read and understand instruction manual.
For safe operation an adequate supply of fresh uncontaminated
air for combustion and ventilation must be provided.
An insufficient supply of air can cause recirculation of combustion
products resulting in contamination that may be hazardous to
life. Such a condition often will result in a yellow, luminous burner
flame, causing sooting of the combustion chamber, burners and
flue tubes and creates a risk of asphyxiation.
Do not install the water heater in a confined space unless an
adequate supply of air for combustion and ventilation is brought
in to that space using the methods described in the Confined
Space section that follows.
14