Wire Labeling

■Each wire coming from the wall to the existing thermostat is connected to a terminal point on that thermostat. Each of these terminal points is usually marked with a code letter as shown in Table A on the next page.

■Note that this thermostat has multiple function terminals that allow Single-Stage Heat Pump ca- pability. Standard systems use: Rh, Rc, G, W. [Single-Stage Heat Pumps use: Rh, Y1, G, and O or B.] Table A below shows the multiple functions of the terminals. Use the terminals that match your system.

■The number of wires in your system can be as few as two (for heat only systems), as many as eight, or any number in between. If you follow the label- ing procedures correctly, you do not have to be concerned about how many wires there are.

■There is often no ter-

minal marking on the

existing thermostat of G Y

two wire, heat only

W

RH

 

 

systems. Just connect

 

 

either of the wires to

 

 

the RH terminal, then

 

 

connect the other wire

 

 

to the W terminal to

 

 

complete the circuit.

 

 

9

■IMPORTANT! BEFORE DISCONNECTING ANY WIRES, APPLY THE SELF-ADHESIVE LABELS PRO- VIDED TO THE WIRE AS SHOWN IN TABLE A ON THE NEXT PAGE. (For example, attach the label marked W to the wire that goes to the W or H terminal on your existing thermostat.) IGNORE THE COLOR OF THE WIRES since these do not always comply with the standard.

■After labeling wires, disconnect them from the existing thermostat terminals.

■Remove existing wallplate. To make sure wires do not fall back into wall opening, you may want to tape them to the wall.

■If hole in wall is larger than necessary for wires, seal this hole with insulating material so that no hot or cold air can enter the back of the thermo- stat from the wall. This air could cause a false thermostat reading.