9
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
two wire, heat only
systems. Just connect
either of the wires to
the RH terminal, then
connect the other wire
to the W terminal to
complete the circuit.
■
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.
W
G
Y
RH
RC
(continued)
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