507713-01
Page 5 of 32
Issue 1623
General
These instructions are intended as a general guide and do
not supersede local codes in any way. Consult authorities
having jurisdiction before installation.
In addition to the requirements outlined previously, the
following general recommendations must be considered
when installing one of these furnaces:
•
Place the furnace as close to the center of the air
distribution system as possible. The furnace should
also be located close to the chimney or vent termination
point.
•
Do not install the furnace where drafts might blow
directly into it. This could cause improper combustion.
•
Do not block the furnace combustion air openings with
clothing, boxes, doors, etc. Air is needed for proper
combustion and safe unit operation.
•
When the furnace is installed in an attic or other
insulated space, keep insulation away from the furnace.
NOTE:
The Commonwealth
of
Massachusetts stipulates
these additional requirements:
•
Gas furnaces shall be installed by a licensed plumber
or fitter only.
•
The gas cock must be “T handle” type.
•
When a furnace is installed in an attic, the passageway
to and service area surrounding the equipment shall be
floored.
Combustion, Dilution & Ventilation Air
In the past, there was no problem in bringing in sufficient
outdoor air for combustion. Infiltration provided all the air that
was needed. In today’s homes, tight construction practices
make it necessary to bring in air from outside for combustion.
Take into account that exhaust fans, appliance vents,
chimneys, and fireplaces force additional air that could be
used for combustion out of the house. Unless outside air is
brought into the house for combustion, negative pressure
(outside pressure is greater than inside pressure) will build
to the point that a downdraft can occur in the furnace vent
pipe or chimney. As a result, combustion gases enter the
living space creating a potentially dangerous situation.
In the absence of local codes concerning air for combustion
and ventilation, use the guidelines and procedures in this
section to install these furnaces to ensure efficient and safe
operation. You must consider combustion air needs and
requirements for exhaust vents and gas piping.
A portion of this information has been reprinted with
permission from the National Fuel Gas Code (ANSI-Z223.1).
This reprinted material is not the complete and official
position of the ANSI on the referenced subject, which is
represented only by the standard in its entirety.
Insufficient combustion air can cause headaches,
nausea, dizziness or asphyxiation. It will also cause
excess water in the heat exchanger resulting in rusting
and premature heat exchanger failure. Excessive
exposure to contaminated combustion air will result
in safety and performance related problems. Avoid
exposure to the following substances in the combustion
air supply:
Permanent wave solutions
Chlorinated waxes and cleaners
Chlorine base swimming pool chemicals
Water softening chemicals
De-icing salts or chemicals
Carbon tetrachloride
Halogen type refrigerants
Cleaning solvents (such as perchloroethylene)
Printing inks, paint removers, varnishes, etc.
Hydrochloric acid
Antistatic fabric softeners for clothes dryers
Masonry acid washing materials
WARNING
The State of California has determined that this product
may contain or produce a chemical or chemicals, in
very low doses, which may cause serious illness or
death. It may also cause cancer, birth defects or other
reproductive harm.
WARNING
