Installation Instructions; Remove And Replace The Old Thermostat; Wire Connections - Daikin TSTATD4271C Installation And Maintenance Manual

Installation Instructions

Remove and Replace the Old Thermostat

To install the thermostat properly, please follow these step by
step instructions. If you are unsure about any of these steps,
call a qualified technician for assistance.
• Assemble tools: Flat blade screwdriver, wire cutters and
wire strippers.
• Make sure your Heater/Air Conditioner is working
properly before beginning installation of the thermostat.
• Carefully unpack the thermostat. Save the screws, any
brackets, and instructions.
• Turn off the power to the Heating/Air Conditioning system
at the main fuse panel. Most residential systems have a
separate breaker for disconnecting power to the furnace.
• Remove the cover of the old thermostat. If it does not
come off easily, check for screws.
• Loosen the screws holding the thermostat base or
subbase to the wall and lift away.
• Disconnect the wires from the old thermostat. Tape the
ends of the wires as you disconnect them, and mark them
with the letter of the terminal for easy reconnection to the
new thermostat.
• Keep the old thermostat for reference purposes, until your
new thermostat is functioning properly.
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igh esoluTion

Wire Connections

If the terminal designations on your old thermostat do not
match those on the new thermostat, refer to the chart below or
the wiring diagrams that follow.
Table 22: TSTATD4271CGT Terminal Designations
Wire from the
old thermostat
terminal marked
G or F
Y1, Y or C
W1, W or H
Rh, R, M, Vr, A
C
O/B
W2
Y2
W3
OUT -
OUT +
S1
S2
* O/B is used if your system is a Heat Pump
Table 23: TSTATD4272CGT Terminal Designations
Wire from the
old thermostat
terminal marked
G or F
Y1, Y or C
W1, W or H
Rh, R, M, Vr, A
C
O/B
W2
Y2
W3
HUM
DEHUM
S1, OUT -
S2, OUT +
* O/B is used if your system is a Heat Pump
57
T s D
ouCh Creen igiTal
Install on the
Function new thermostat
connector marked
Fan
Cooling
Heating
Power
Common
Rev. Valve W1/O/B*
2nd Stage Heat
2nd Stage Heat
3rd Stage Cooling
Outdoor Sensor SENSOR
Outdoor Sensor SENSOR
Remote Sensor SENSOR
Remote Sensor SENSOR
Install on the
Function new thermostat
connector marked
Fan
Cooling
Heating
Power
Common
Rev. Valve W1/O/B*
2nd Stage Heat
2nd Stage Heat
3rd Stage Cooling
Humidity
Dehumidity
Outdoor Sensor OUTDOOR
Outdoor Sensor OUTDOOR
IM 1227 • MODELS DC THERMOSTATS
T
hermosTaT
G
Y1
W1/0/B
R
C
W2
Y2
W3
G
Y1
W1/0/B
R
C
W2
Y2
W3
HUM
DEHUM