Instructions / Assembly

11
Outdoor and Indoor Stacks
The outdoor and indoor stacks are optional equipment and
do not come standard with the heater. Refer to installation
instructions inside box for instructions on how to install
outdoor/indoor stack.
Model Outdoor Stack Indoor Stack
206A 009834 009838
266/266A 009835 009839
336A 009836 009840
399/406A 009837 009841
Table D. Outdoor and Indoor Stack Kit Number
OUTDOOR STACK KIT
(1) Outdoor drafthood, painted
(1) Adapter plate
(3) Mounting brackets (clips)
(1) Top panel cover
(2) 1-foot sections of metal tape
(3) Screws
(1) Instructions
Clips
Figure 6. Outdoor Stack Kit Components
NOTE: The outdoor drafthood kit does not require any
additional vent pipe for proper operation. This drafthood
functions as the vent termination.
INDOOR STACK KIT
(1) Drafthood, unpainted
(1) Adapter plate
(3) Mounting brackets (clips)
(3) Screws
(1) Instructions
Clips
Figure 7. Indoor Stack Kit Components
Combustion and Ventilation Air
Indoor Units Only
The heater must have both combustion and ventilation
air. The minimum requirements are listed in the latest
edition of the National Fuel Gas Code (U.S. ANSI Z223.1
or Canada CAN/CSA-B149) and any local codes that
may have jurisdiction. The most common approach is
the "2-opening" method, with combustion air opening no
more than 12" from the floor and the ventilation opening
no more than 12" from the ceiling. For opening sizes
using this method, see below.
All Air from Inside the Building:
Each opening shall have a minimum net free area as noted:
Model Sq. in. (m
2
)
206A 200 (0.13)
266/266A 266 (0.17)
336A 333 (0.21)
399/406A 399 (0.26)
Table E. Opening Minimum Net Free Requirements -
Indoor Air
All Air from Outdoors:
When air is supplied directly from outside the building, each
opening shall have a minimum net free area as noted:
Model
Unrestricted
Opening
sq. in. (m
2
)
Typical Screened or
Louvered Opening
sq. in. (m
2
)
Typical Screened
and Louvered
Opening
sq. in. (m
2
)
206A 50 (0.03) 75 (0.05) 100 (0.06)
266/266A 67 (0.04) 101 (0.06) 134 (0.09)
336A 84 (0.05) 126 (0.08) 168 (0.11)
399/406A 100 (0.06) 150 (0.1) 200 (0.13)
Table F. Opening Minimum Net Free Requirements -
Outdoor Air
A
CAUTION: Combustion air must not be contaminated
by corrosive chemical fumes which can damage the
heater. Such damage will not be covered by the warranty.