Venting - Lennox LF24-100 Installation Instructions Manual

2 − If the inducer is to be rotated, follow the instructions
in this section; otherwise, refer to instructions under
Venting" section.
3 − Before making an electrical or gas connections,
remove the securing
box/combustion air inducer. See figure 1.
FLUE BOX AND
COMBUSTION AIR INDUCER ASSEMBLY
FLUE BOX GASKET
FLUE BOX
VEST PANEL
COMBUSTION AIR INDUCER GASKET
COMBUSTION AIR INDUCER
FIGURE 1
4 − Remove the flue box/combustion air inducer
assembly, ensuring that the gasket is not damaged.
If the gasket is damaged, replace it.
5 − Use a 1/4" socket to remove the three screws which
secure the combustion air inducer to the flue box.
Remove the inducer and gasket from the flue box
ensuring that the gasket is not damaged. If the
gasket is damaged, replace it.
6 − Use the template provided in the back of this manual
to mark new hole locations. Use a 7/32" drill bit to
drill holes in flue box.
7 − Place the gasket between the combustion air
inducer and the flue box. Rotate both the inducer
and the gasket 90° to the desired position. Reinsert
and tighten the three inducer securing screws
(#8−16 X 1/2" HWHSMS).
8 − Place the gasket between the flue box and the vest
panel. Position the flue box/combustion air inducer
assembly on the vest panel. Fasten the flue box to
the vest panel using the flue box securing screws
(#10−16 X 5/8" HWHSMS) and a 5/16" driver.
screws on the flue
Page 5
9 − The unit heater is now ready for installation as
described in the Venting section.

Venting

NOTE − The vent is a passageway, vertical or nearly so,
used to convey flue gases from an appliance, or its vent
connector, to the outside atmosphere. The vent
connector is the pipe or duct that connects a fuel−gas
burning appliance to a vent or chimney.
NOTE − Local codes may supersede any of these
provisions.
GENERAL RECOMMENDATION AND REQUIREMENTS
LF24 unit heaters must be vented in compliance with the
latest edition of the National Fuel Gas Code (NFPA 54 /
ANSI Z223.1) in the USA and with CSA−B149.1 codes in
Canada, as well as applicable provisions of local building
codes, and the following instructions.
A sheet metal flue transition is supplied with this
certified unit. It must not be modified or altered and
must be installed on the outlet of the combustion air
inducer assembly prior to the installation of the vent
connector. Failure to comply with this requirement
will void the certification of the unit by the approval
agencies.
A single−wall vent connector may be used in all
applications between the furnace and the vertical vent
pipe.
A single−wall vent pipe used as a vent connector or as a
vertical vent, must have all seams and joints sealed with
pressure−sensitive aluminum tape or silicone rubber
sealant. Aluminum tape must meet the provisions of
SMACNA AFTS−100−73 Standards. The aluminum tape
must have a temperature rating of 400°F (204°C).
Silicone rubber sealant must have a temperature rating of
482°F (250°C), i.e., Dow Corning RTV−736 or equivalent.
All joints must be secured with at least two corrosion
resistant screws. All joints must be checked for gas
tightness after installation. Single−wall vent pipe used as
vertical vent must not pass through any attic, interior wall,
concealed space, or floor.