Honeywell RTH8500 Series User Manual page 11

Installing your thermostat
8 Install battery.
Insert the coin cell battery
(included), observing the
correct polarity.
A correctly inserted
Note:
battery will extend about halfway
out of the battery slot on the
thermostat, allowing for easier
removal.
This battery maintains time and
date during power outages. It
does not power the thermostat
(C wire required).
9 Attach thermostat to wallplate.
Align the thermostat to the wallplate
and then snap into place.
10 Switch heating/cooling system ON.
Important!
10a Verify that the C wire is
connected at the thermostat
and at the heating/cooling
system.
10b Make sure the heating/
cooling system door is firmly
secured.
10c Switch power back ON for
your heating/cooling system
at the breaker box or its
power switch.
Thermostat interior
Wallplate
L
AUX
/E
K
breaker
9
HEAT PUMP
CONVENTIONAL
Y2 RC RC
M31543
R R
W2 W O/B
K Y Y
G G
C C
Thermostat
or
Circuit Heating/cooling
system power
box switch
33-00133ES—01