Switch B - Setback Recovery (Active on all models)
Selects between normal and smart recovery from setback. Normal
recovery changes to the new setpoint at the programmed time.
Smart recovery, which is active in heating mode only, starts earlier
and adjusts the setpoint slowly so that room temperature will arrive
at the programmed temperature at the programmed time.
TO SET:
OFF—for smart recovery. This is the factory default.
ON—for normal recovery.
Switch C - HP/AC Select (Active on HP and 2S models only)
Use to select between AC and HP installations. HP and 2S models
have an extra relay to control the HP reversing valve. When a HP
thermostat is placed in the AC mode, this extra relay is converted
to a second stage heat output. This allows thermostat control of
2-stage furnaces or 2-stage strip heat with AC systems. (AC mode
also uses W rather than Y for first-stage heat.)
TO SET:
OFF—for HP applications. Extra relay controls reversing valve.
This is factory default.
ON—for AC applications. Extra output can be used for 2-stage
heat.
Switch D - Staging Select (Active on 2S models only)
This switch converts a 2-speed heat pump thermostat with 1 stage
of auxiliary heat into a 1-speed heat pump thermostat with 3 stages
of auxiliary heat for comfortable leaving air temperature. It
requires selected heaters with 2:1 ratio element sizes plus an FK4
fan coil. Refer to FK4 fan coil literature for details.
TO SET:
OFF—for normal 2-speed operation. This is factory default.
ON—for special 3-stage heat with FK4 fan coil.
Step 3—Install Thermostat
Before installing thermostat, turn off all power to unit. There
may be more than 1 power disconnect. Electrical shock can
cause personal injury or death.
1. Turn OFF all power to unit.
2. If an existing thermostat is being replaced:
a. Remove existing thermostat from wall.
b. Disconnect wires from existing thermostat, 1 at a time. Be
careful not to allow wires to fall back into the wall.
c. As each wire is disconnected, record wire color and
terminal marking.
d. Discard or recycle old thermostat.
NOTE:
Mercury is a hazardous waste and MUST be disposed of
properly.
3. Open thermostat rear door (mounting base) to expose mount-
ing holes. The base can be removed to simplify mounting.
Snap apart carefully at hinge to separate mounting base from
remainder of thermostat.
4. Route thermostat wires through large hole in mounting base.
Level mounting base against wall (for aesthetic value
only—thermostat need not be leveled for proper operation)
and mark wall through 2 mounting holes.
5. Drill two 3/16-in. mounting holes in wall where marked.
6. Secure mounting base to wall with 2 screws and anchors
provided, (additional anchoring holes available for more
secure mounting if needed) making sure all wires extend
through hole in mounting base.
7. Adjust length and routing of each wire to reach proper
terminal and connector block on mounting base with 1/4 in. of
extra wire. Strip only 1/4 in. of insulation from each wire to
prevent adjacent wires from shorting together when con-
nected.
8. Match and connect equipment wires to proper terminals of the
connector blocks. (See Table 1, and Fig. 2 through 24.) Both
R and C must be connected for proper thermostat operation.
Improper wiring or installation may damage the thermostat.
Check to make sure wiring is correct before proceeding with
installation or turning on unit.
9. Push any excess wire into wall and against mounting base.
Seal hole in wall to prevent air leaks. Leaks can affect
operation.
10. Snap hinge back together.
11. Close thermostat assembly making sure pins on back of circuit
board align with sockets in connector.
12. Turn ON power to unit.
On power up, display shows selected setup mode AC, HP, A2, H2,
or HS for a few seconds depending on model and DIP switch
settings.
Step 4—Set Thermostat Configuration
Configuration options, like DIP switch settings, are intended to be
selected at installation and normally are not modified by the
homeowner. These options are not discussed in the homeowner’s
manual and therefore must be made as part of the installation. A
special procedure allows entry into the configuration mode. The
thermostat will automatically exit this mode if no button is pressed
for 10 seconds. While in configuration mode, 5 option choices can
be made:
1. Fahrenheit or Celsius—Selection.
2. G (Fan) ON with any W (Heat)—Selection.
3. High ambient heat lockout (HP and 2S models
only)—Selection and Value Adjustment.
4. Clean filter timer—Selection and Value Adjustment.
5. ’Anticipator’—Value Adjustment.
An explanation for each of these and how to enter the configura-
tion mode follows.
Table 1—Model Selection and Wiring Diagram Chart
OUTDOOR
UNIT
AIR CONDITIONER
HEAT PUMP
1 Speed
2 Speed
1 Speed
2 Speed
1-Stage
Furnace
Model AC
See Fig. 2
Model 2S
See Fig. 8
Requires Interface Control
or Dual Fuel Thermostat
Model 2S
See Fig. 11
2-Stage
Furnace
Model AC
See Fig. 3
Model HP
See Fig. 4
Model 2S
See Fig. 9
Requires Interface Control
or Dual Fuel Thermostat
Model 2S
See Fig. 12
Typical Fan Coil
Model AC
See Fig. 5
Model HP
See Fig. 6
Model 2S
See Fig. 10
Model HP
See Fig. 7
Model 2S
See Fig. 13
→
FK4C
Fan Coil
Model AC
See Fig. 15
Model HP
See Fig. 16
Model 2S
See Fig. 17
Model 2S
See Fig. 14
Model 2S
See Fig. 18
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