Honeywell 7-Day Programmable Thermostat (RTH7600D) Owner's Manual

Turn thermostat over, insert 

fresh AA alkaline batteries, 

then reinstall thermostat.

Battery replacement

M28420

Batteries are optional (to provide 

backup power) if your thermostat 

was wired to run on AC power when 

installed.
Install fresh batteries immediately when 

the LO BATT warning begins flashing. 

The warning flashes about 30 days 

before batteries are depleted.
Even if the warning does not appear, 

you should replace batteries once a 

year, or before leaving home for more 

than a month.

Grasp thermostat and pull to 

remove from wallplate

M28419