Ecobee Smart Si - Page 16

11
YRWGR
1-stage AC
C
24V
Y
G
R
W
C
HUM
1-stage Furnace
Original Thermostat
YN/C
W
O/B
GRCRHCY2
W2
AUX
1-stage AC
C
24V
Y
G
R
W
C
HUM
1-stage Furnace
Smart Si Thermostat
Use jumper
wire included
in box
Repurpose G
wire as C wire
Use jumper wire included in box to connect Y and G on the furnance
Repurpose the original G wire as C wire. Note that the furnance controls the fan in this
conguration.
Single stage heat/cool with 4 wires at thermostat
Before
After