TH8320U AND TH8321U TOUCH SCREEN PROGRAMMABLE THERMOSTATS
Do not install the thermostat where it can be affected by:
— Drafts or dead spots behind doors and in corners.
— Hot or cold air from ducts.
— Radiant heat from sun or appliances.
— Concealed pipes and chimneys.
— Unheated (uncooled) areas such as an outside wall
behind the thermostat.
Installing Wallplate
CAUTION
Electrical Hazard.
Can cause electrical shock or equipment
damage.
Disconnect power before wiring.
The thermostat can be mounted horizontally on the wall
or on a 4 in. x 2 in. (101.6 mm x 50.8 mm) wiring box.
1. Position and level the wallplate (for appearance
only).
2. Use a pencil to mark the mounting holes.
WALL
WIRES THROUGH WALL
AND WIRE SLOT
MOUNTING
HOLES (2)
MOUNTING
SCREWS (2)
Fig. 2. Mounting wallplate.
3. Remove the wallplate from the wall and, if drywall,
drill two 3/16-in. holes in the wall, as marked. For
firmer material such as plaster, drill two 7/32-in.
holes. Gently tap anchors (provided) into the drilled
holes until flush with the wall.
4. Position the wallplate over the holes, pulling wires
through the wiring opening. See Fig. 2.
5. Insert the mounting screws into the holes and
tighten.
WIRING (FIG. 5-16)
All wiring must comply with local electrical codes and
ordinances.
1. Select set of terminal identifications (Table 2) that
corresponds with system type (conventional or
heat pump in Fig. 3).
2. Loosen the screws for the appropriate system type
selected; see Table 2. Insert wires in the terminal
block under the loosened screw. See Fig. 4.
69-1706
WALL ANCHORS (2)
M19916
3. Securely tighten each screw.
4. Push excess wire back into the hole.
5. Plug the hole with nonflammable insulation to
prevent drafts from affecting the thermostat.
Y2
Y2
L
E
AUX
W2
S1
S1
S2
S2
Fig. 3. Selecting terminal identifications for
system type.
Table 2. Selecting Terminal Identifications for
System Type.
System Type
Standard Heat/Cool
Heat Only
Heat Only with Fan
Heat Only Series 20
Cool Only
Standard Multistage
up to 2 Heat/2 Cool
Heat Pump with No
Auxiliary Heat
Heat Pump with
Auxiliary Heat
Fig. 4. Inserting wires in terminal block.
IMPORTANT
Use 18 gauge thermostat wire.
2
HEAT PUMP
CONVENTIONAL
RC
RC
R
R
W
O/B
Y
Y
G
G
C
C
SCREW TERMINALS
M19951
Wallplate
Terminal
Diagram
Identifications
Reference
Conventional
Conventional
Conventional
Conventional
Conventional
Conventional
Heat Pump
Heat Pump
M19917
Wiring
5, 6
7
8
9
10
11, 12
13, 14
15, 16