Page 1
CFSB17, CFSB21, CFSB24
®
g
COUNTERFLOW FL OOR SUB-BASE KIT
INSTALLATION INSTRUCTIONS
Description
The Counterflow Floor Sub-Base (CFSB) accessory prevents excessive temperatures from reaching combustible materials by
effectively separating the furnace base and plenum from the combustible material. This accessory must be used if the furnace is
installed on a combustible floor. To ensure a safe installation, do
not install the counterflow floor sub-base directly on carpeting,
tile, or other combustible material other than wood flooring.
Follow the instructions below.
KIT Installation
Ensure all parts are included before beginning. If parts are missing contact the dealer where the kit was purchased.
1. Determine the furnace location and select the appropriate
sub-base kit.
2. Cut the floor opening to match dimensions shown in the
table and figure for selected sub-base.
3. Set sub-base into floor opening.
4. Size plenum to match dimensions shown in table for selected sub-base. Bend a 5/8” outward flange on plenum
back and sides. Leave 5/8” straight on plenum front.
5. Insert the plenum up through the sub-base, placing the
supplied insulation strips between the sub-base and the
plenum flanges as shown in figure.
6. Place the remaining supplied insulation strips between the
plenum flanges and the furnace taking care not to damage
insulation.
7. Secure plenum, sub-base and furnace into place.
CFSB17
CFSB21
CFSB24
MODELSCFSB
B wid th
models
C wi dth
models
D width
models
DIMENSIONS, INCHES
ABCDEFG
18-9/16 23-3/4 29 18-1/2 17-1/2 16 1-11/32
18-9/16 23-3/4 29 22 21 19 1/2 1-11/32
18-9/16 23-3/4 29 25-1/2 24-1/2 23 1-11/32
Furnace
Unit
Plenum
IO-827
August 2014
D
C
FURNACE
MODELS
B Width
Model s
C Wi dth
Model s
D Width
Model s
F
E
B
A
G
Goodman Manufacturing Company, L.P.
5151 San Felipe, Suite 500, Houston, TX 77056
www.daikincomfort.com, www.goodmanmfg.com and www.amana-hac.com
© 2014 Goodman Manufacturing Company, L.P.
is a registed trademark of Maytag Corporation or its related companies and is used under license to
Goodman Company, L.P., Houston, TX, USA. All rights reserved.
COUNTERFLOW
BASE #
CFSB17 17-1/2 23-3/4 16 18-9/16
CFSB21 21 23-3/4 19-1/2 18-9/16
CFSB24 24-1/2 23-3/4 23 18-9/16
FLOOR OPEN I NG PLENUM S IZ E
HJKL
Floor
openin
Loading...