37
GA
S
O
GAS-EL
ELEC
B
HP
Check Dip Switch
Ensure which switch is correct for your system. Dip
switches are located on the back of the thermostat.
1. When
GAS/EL or HP
is set for
GAS/EL:
This switch (GAS or ELEC) controls how the
thermostat will control the Fan (G) terminal in
heating mode. When
GAS
is chosen, the
thermostat
will not
energize the Fan (G)
terminal in heating. When
ELEC
is chosen the
thermostat
will
energize the fan in heating.
2. When
GAS/EL or HP
is set for
HP
:
This switch (GAS or ELEC) defines the Aux Heat type.
When
GAS
is chosen, the auxiliary heat will not be
allowed to run during heat pump operation. When
using a Dual Fuel system, set this switch for
GAS
(T3950-IAQ)
. When
ELEC
is chosen, up to two
stages of auxiliary strip heat will be allowed to run.
For Heat Pump Only
When the GAS/EL or HP dip switch is configured
for HP, this dip switch (O or B) must be set to
control the appropriate reversing valve. If O is
chosen, the W1/O/B terminal will energize in
cooling. If B is chosen, the W1/O/B terminal
will energize in heating.
This dip switch configures the thermostat to
control a conventional gas/electric system or a
heat pump. If your system is anything other than
a heat pump, leave this switch set for
GAS/EL.
Installation Instructions