Honeywell FOCUSPRO TH5320R Operating Manual page 14

Battery replacement (outdoor air sensor)
Remove cover
and install 2
fresh AA lithium
batteries
Remove sensor
from bracket
Replace outdoor sensor batteries when
the
REPLACE BATTERY OUTDOOR
flashing on the thermostat. The warning
flashes about two months before the bat-
teries are depleted.
Remove the sensor from the bracket,
remove the cover and install 2 fresh AA
lithium batteries.
After batteries are installed, the sensor
will automatically restore communication
with the wireless network within a few
minutes.
12
warning begins