Sample Wiring Diagrams
5 Conductor 18 to 22 gauge
unshielded cable from the
thermostat to the equipment.
FAN
G
POWER
R B
REVERSING VALVE
COMPRESSOR
Y
AUXILIARY HEAT
W
Page 16
OWNER'S MANUAL
S1-THEH21NS
Common wire optional
*
*
C
R
Y
W
G
B
O
5 Wire, 1 Stage Cooling, 2 Stage Heat-Heat Pump with B reversing valve.
Residential Heat Pumps, split systems & package units, with auxiliary heat.
Common wire is optional in all installations. If a common wire is not used the
thermostat must be powered by two AA alkaline batteries. These batteries
must be replaced (page 11) each year or when the Low Battery indicator is displayed
(page 3).