RC RC 24VACPowersupplyforCooingsde
RC RH 24VACPowers_lpplyforHeatingside
C C 24VACcornmonforcorltrdcirc/litandthermostatpowerinput
L System Monitor No use
Y1 Y1 1st stage cornpresor 1st stage coding
Y2 Y2 2nd stage cornpressor 2nd stage coding
W1 W1 Emergerlcy Heat: 1st stage heating
OiB W2 Changeover valve 2nd stage heating
G G Fan
X X Reserve for future
3_ LabeZ _2fms
Check the existing thermostat wire terminal identification carefully, and apply the wiring
labels provided with the Smart Thermostat to the wires with the same identification. This
will allow you to connect the wires to the correct terminals on the new Smart Thermostat
back plate. For a conventional system (Non-Heat Pump marked as Non--HP) you may find
some of the following terminals connected: RC RH C Y1 Y2 W1 W2 and G. For a heat
pump system(HP) you may find some of the foJJowlng terminals connected: R C L Y1
Y2 Wl O/BandG. Use the label set from the left or r ght side of the terminal strip that
matches your HVAC system (marked NomHP or HP).
4_ Dfscor_rtect _u2fresarid remove bacl_ Sate
Remove the wires from the exist[rig thermostat back pJate and remove the back plate from
the walJ.
Note: Keep the heating/cooling system power OFF to avoid risk of inju_]y.
large trim
back plate plate
5_ Determfrte i/y;ou need t£e
[czr_etrfm Sate
if the holes that are [eft in the walJ from
removal of the old back plate take up more
space than the new back pJate, install the
new back pJate OVER the new [arge trim
plate, as shown above. Skip to step 6if the
hoJes that are [eft in the walJ take up less
space than the new back pJate,
Use a drill, screws and the plastic anchors
to install both plates as shown above to the
wall, If the old thermostat was installed into
a standard metal or plast c electrical box with
or without conduit, save and use the screws
that were used. You will not need the wall
anchors,
Make sure the _ symbol on the back
plate is pointing upward,