INSTALLATION
REMOVE OLD THERMOSTAT
Screw anchors
1. Shut off electricity at the main fuse box until installation is
complete. Ensure that electrical power is disconnected.
2. Remove the front cover of the old thermostat. With wires
still attached, remove wall plate from the wall. If the old
thermostathasawallmountingplate,removethethermostat
and the wall mounting plate as an assembly.
3. Identifyeachwireattachedtotheoldthermostatusingthe
labels enclosed with the new thermostat.
4. Disconnect the wires from old thermostat one at a time. DO
Mounting
holes
NOT LET WIRES FALL BACK INTO THE WALL.
Electric/Gas
switch
5. Install new thermostat using the following procedures.
Mounting
holes
ATTENTION!
Figure 1. Thermostat Base
This product does not contain mercury. However, this product
may replace a unit which contains mercury.
6. Push excess wire into wall and plug hole with a fire-resistant
material(suchasfiberglassinsulation)topreventdraftsfrom
affecting thermostat operation.
Do not open mercury cells. If a cell becomes damaged, do not
touch any spilled mercury. Wearing nonabsorbent gloves, take
up the spilled mercury and place into a container which can be
sealed. If a cell becomes damaged, the unit should be dis-
carded.
HYDRONIC (HOT WATER OR STEAM)
HEATING SYSTEMS
Mercury must not be discarded in household trash. When the
unit this product is replacing is to be discarded, place in a
suitable container and return to White-Rodgers at 9797 Reavis
Road, St. Louis, MO, 63123-5398 for proper disposal.
This thermostat is set to operate properly with a forced-air
heatingsystem.Ifyouhaveahydronicheatingsystem(asystem
that heats with hot water or steam), you must set the thermostat
tooperateproperlywithyoursystem. Changethesecondoption
intheconfigurationmenutoSL(seeCONFIGURATIONMENU,
page 4).
ELECTRIC HEAT OR SINGLE-STAGE
HEAT PUMP SYSTEMS
Read entire paragraph before setting electric heat switch. If you
are unsure of your application, contact a qualified service
person.
CHECK THERMOSTAT OPERATION
If at any time during testing your system does not operate
properly, contact a qualified service person.
If you have a single-stage heat pump system, OR your system
uses central electric heat, where the blower is energized by a
separate circuit through the fan relay (meaning that the fan
turns on immediately on call for heat), then the switch on the
thermostat base must be moved to the “ELECTRIC” position
(see fig 1). If the thermostat is energizing electric heat sequenc-
ers, the switch MUST remain in the “GAS” position.
Turn on power to the system.
Fan Operation
If your system does not have a G terminal connection, skip to
Heating System.
1. Move fan switch to ON position. The blower should begin to
If you must move the switch to the “ELECTRIC” position (to the
left), use a small screwdriver or pencil.
operate.
2. Move fan switch to AUTO position. The blower should stop
immediately.
ATTACH THERMOSTAT BASE TO WALL
Heating System
1. Remove the packing material from the thermostat. Gently
pull the cover straight off the base. Forcing or prying on the
thermostatwillcausedamagetotheunit. Ifnecessary, move
the electric heat switch (see ELECTRIC HEAT SYSTEMS,
above).
1. Move SYSTEM switch to HEAT position. If the heating
system has a standing pilot, be sure to light it.
2. Press
toadjustthermostatsettingaboveroomtempera-
ture. The heating system should begin to operate.
2. Connect wires beneath terminal screws on base using
appropriate wiring schematic (see figs. 2 through 7).
3. Press
to adjust temperature setting below room tem-
perature. The heating system should stop operating.
3. Place base over hole in wall and mark mounting hole
locations on wall using base as a template.
Cooling System
4. Move base out of the way. Drill mounting holes.
5. Fasten base loosely to wall, as shown in fig. 1, using two
mounting screws. Place a level against bottom of base,
adjust until level, and then tighten screws. (Leveling is for
appearance only and will not affect thermostat operation.) If
you are using existing mounting holes, or if holes drilled are
too large and do not allow you to tighten base snugly, use
plastic screw anchors to secure subbase.
CAUTION
!
Topreventcompressorand/orpropertydamage, ifthe
outdoor temperature is below 50°F, DO NOT operate
the cooling system.
1. Move SYSTEM switch to COOL position.
2