Venstar T7900 - Manual (Page 85)

77
GAS/EL
12
3
ON
HP
O
GAS
B
ELEC
12
3
ON
12
3
ON
GAS/EL HP HP GAS/EL
OR
1
2
3
ON
1
2
3
ON
O O B B
OR
GAS ELEC GAS ELEC
OR
1
23
ON
1
23
ON
SENSOR
Installation Instructions
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.*
*For some commercial heat pumps, this switch may need
to be set for GAS/EL. Consult the commercial heat pump
literature.
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.
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.
When ELEC is chosen, up to two stages of auxiliary
strip heat will be allowed to run.
Explanation of Thermostat Dip Switches
Dip switches are located on the back of the thermostat