Honeywell T6 Pro - Setting Slider Tabs; Wiring Terminal Designations

Conventional Systems Heat pump systems
Terminal Description Terminal Description
S/S
Input for a wired indoor,
outdoor sensor
S/S
Input for a wired indoor,
outdoor sensor
Y Compressor Stage 1 Y Compressor Stage 1
Y2 Compressor Stage 2 Y2 Compressor Stage 2
G Fan Relay G Fan Relay
C
24VAC Common wire
from secondary side of
cooling transformer (if 2
transformers)
C
24VAC Common wire
from secondary side of
cooling transformer
K*
Connect to K on C-wire
adaptor
K*
Connect to K on C-wire
adaptor
U/U** Relay for ventilation U/U** Relay for ventilation
A L/A
Connect to compressor
monitor
W Heat Stage 1 O/B
Changeover valve for
heat pumps
W2 Heat Stage 2 Aux Backup Heat
E Emergency Heat