Terminal Designator Descriptions
1
ST
Cool
2
ND
Cool
1
ST
Heat
2
ND
Heat
Heat Pump (One Compressor)
Y1, G, O
Y1, G, O
Y1, G, B
Y1, W2, G, B
Heat Pump (Two Compressors)
Y1, G, O
Y1, Y2, G, O
Y1, G, B
Y1, Y2, G, B
Emergency Heat
N/A
N/A
E, G
E, W2, G
SC4211 Output Chart
L – Service Led indicator
R – 24 VAC hot
C – 24 VAC common
O/B – Configurable
O – cool active reversing valve
B – heat active reversing valve
Y1 – 1st stage cool, 1st stage heat
W2 – 2nd stage heat for single compressor systems, 2nd stage for Emergency heat
Y2 – 2nd stage cool for 2 compressor systems, 2nd stage heat for 2 compressor systems
G – Fan
E – 1st stage heat for Emergency heat mode
The SC4211 thermostat is configurable for most heat pump systems . The configuration directly affects
the outputs .
Use the output chart to correctly configure and wire the thermostat to your system .
