3M 3M-08 Install Manual - Remove Old Unit

Remove old unit

Label Wires to Old Unit

Mount the 3M-08

Separate front from back of unit. Grasp the 

front of the unit and the back of the unit and  pull apart. 

The thermostat body away from the base.

Hold the base against the wall, with the wires coming 

through the opening below the terminal block. 

Position the base for best appearance 

The 3M-08 can be mounted vertically or horizontally. 

chose the position that best suites your wall.

Attach the base to the wall with the two screws 

provided.

If you are mounting the base to sheet rock or if 

you are using the old mounting holes, use the 

plastic anchors provided. 

Drill a 3/16-in.(4.8mm) 

hole for the insert at 

each screw location, 

then mount the base.

PG

 3

PG

 4

Terminal Block

Switch electricity to the furnace and air conditioner OFF; 

then proceed with the following steps.

Remove cover from old thermostat. Most are snap-on types and simply pull 

off. Some have locking screws on the side or front. These must be loosened.   

Note the letters printed near the terminals. 

Carefully attach labels (enclosed) to each wire. Label the wires one at a time.  

You must have all the wires labeld before you procede. 

Remove the wires from the terminals of the old thermostat.

Make sure the wires do not fall back inside the wall.  

Wind them around a pencil to keep them from falling.

Remove the old thermostat from the wall. Fill wall 

opening with fiber glass insulation to prevent drafts.  

Caution

DO NOT REMOVE WIRES FROM OLD THERMOSTAT UNTIL YOU HAVE 

CAREFULLY LABELED THEM, WITH LABELS PROVIDED.

THERE IS NO STANDARD COLOR CODE FOR THESE WIRES.