Making 4 Wires Work When 5 Wires Are Required - Johnson Controls T9100 Owner's Manual

Installation Instructions

Making 4 Wires Work When 5 Wires Are Required

If you would like to install the JCI thermostat using only 4 wires when 5 are
required, follow the directions below. You will need a screwdriver along
with a 3" long piece of thermostat wire to use as a jumper:
1. Make sure the power is off.
2. Label and disconnect wires at the thermostat. Please note the color
and corresponding wire designator with each color. For example:
The R wire is red and the W wire is white and so on. You will need this
information handy for the next step at the HVAC equipment.
3. At the HVAC equipment end of the thermostat wires (usually at the
furnace), locate the terminals that the wires are attached to.
4. Remove the "G wire" from the terminal marked G.
5. Place the "G wire" on terminal C.
6. Place one end of the 3" long jumper on terminal G.
7. Place the other end of the 3" long jumper on terminal Y. Please note
that there will be more than 1 wire on terminal Y.
8. When connecting the wires to the JCI thermostat, note that the wire
that was previously connected to the G terminal of the old thermostat
will now be required to be connected to the C terminal on the JCI
thermostat. All other wires will be connected such that the connections
on each end of the individual wires match terminal designations.
For example: Connect the yellow wire on the thermostat end to the
Y terminal on the thermostat. The yellow wire will be connected to the
Y terminal on the HVAC equipment end also.
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