7
13. Make sure wire connections are secure.
14. Push excess wire back through opening.
15. Set the Electric/Gas switch to either GAS for a gas/oil heating
system or ELEC for an electric heating system (Figure 5).
16. Set the HP option switch to either the HP for heat pump or
NON_HP for furnace applications (Figure 5).
17. Replace thermostat cover by snapping into place.
R
C
G
O
B
Y1
W1
ELEC GAS
NON_HP HP
°
F
Figure 5
TERMINAL LEGEND - 8401
TERM
EQUIPMENT TO CONNECT
REQ?
TERMINAL FUNCTION
R
24VAC hot connection
Yes
For input of 24VAC hot
connection
C
24VAC common connection
Yes
For input of 24VAC
common side of
transformer
W1
Heat connection
Yes*
Energizes on a call for
heating
Y1
Compressor Connection
Yes*
Energizes on a call for
cooling
B
Heat active reversing valve**
No
Energizes when in the
HEAT mode
O
Cool active reversing valve**
No
Energizes when in the
COOL mode
G
Indoor fan connection
Yes
Energizes with Y1 & W1
terminals or with FAN
option switched to the
ON position
* This thermostat can be used as a heat only or cool only thermostat. Therefore it is not always
necessary to use both Y and W.
**The O and B terminals are accessory terminals that typically are used for heat pump applications.
ELECTRIC/GAS SWITCH
Selects fan control.
HP OPTION SWITCH
Heat pump switch.
110-1087B.qxd 3/4/05 4:00 PM Page 7