Honeywell TH8110U User Manual

69-1700

2

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.

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.

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.

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.

WALL

MOUNTING 
HOLES

M19916

MOUNTING 
SCREWS (2)

WALL ANCHORS (2)

WIRES THROUGH WALL
AND WIRE SLOT

Standard Heat/Cool

Conventional

5, 6

Heat Only

Conventional

7

Heat Only with Fan

Conventional

8

Heat Only Series 20

Conventional

9

Cool Only

Conventional

10

Heat Pump with No 
Auxiliary Heat

Heat Pump

11

CONVENTIONAL

SCREW TERMINALS

HEAT PUMP

M19951

Y2

L

E

AUX

S1

S2

Y2

W2

S1

S2

RC

R

O/B

Y

G

C

RC

R

W

Y

G

C

M19917