Operating Manual

RTH2300/RTH221
17 69-2727EF—03
Battery replacement
Install two fresh AAA batteries when
Lo Batt flashes on the screen. Lo Batt
appears for 60 days before the batter-
ies are depleted.
Replace batteries once a year, or when
you will be away for more than a month.
Most settings are stored in non-volatile
(permanent)memory.Onlytheclock
and the day must be set after you
replace the batteries.
Pull at bottom to
remove thermostat
from wallplate.
Turn thermostat over,
insert fresh AAA alkaline
batteries, then reinstall
thermostat.
SettheSystemswitchtoOffbeforeremovingthe
batteries.Otherwise,theheating/coolingsystemcould
remain activated even when batteries are removed.
RTHXXXX
M32707
W/
Aux
Not
Used
Heat Off Cool Auto On
Fan
M33784
Heat Off Cool Auto On
Fan
Heat Off Cool
Auto On
Fan
Set
Hold
Run