Trane 4TTX8024A - Furnace Wiring Connections; Variable Speed Furnace Wiring

18-AC95D1-1 15
Notes:
1. Installer must cut the
factory R to BK jumper
on furnace circuit board.
OR, on new 15-digit
models, set the S5-2
DIP switch to OFF.
2. Installer must add a
field installed jumper
between R and O on the
furnace terminal strip
3. 4TTX8 units require
80% airflow with Y1 (low
stage) and 100% airflow
with Y2 (high stage).
A) Connect Y1 from
comfort control to
Y at the VS furnace
and to Y1 (yellow/
black) at the AC.
B) Connect Y2 from
comfort control to
BK at the VS furnace
and to Y2 (yellow/
red) at the AC.
4. Comfort control may not
have W2 or W3 termi-
nals.
5. If single stage heating
comfort control is used,
jumper W1 to W2 on the
furnace terminal strip.
Red
Yellow
Brown
Green
White
Black
Blue
W1
B
W2
G
Y2
Y1
R
Comfort Control
Variable Speed
Furnace
Air Conditioner
Yellow
Yellow/Black
Brown
Yellow/Red
Blue
Blue
W1
W2
G
Y
B
O
BK
Y
LO
R
Neatly bundle all low voltage
wires behind the service
valve cover as shown.
Variable Speed Furnace
Hook-up Diagram