Ecobee Smart Si Installation Manual page 19

2-stage AC
Y1
Y2
R
C
Smart Si Thermostat
14
W2
Y2 C RH RC G
AUX
HUM
W
Y N/C
O/B
Dual stage heat, dual stage cool
2-stage Furnace
Y1
W1
G
W2
R
Y2
C