Battery Replacement - Honeywell RTH7400 series Operating Manual

Battery replacement

Grasp thermostat and pull to
remove from wallplate
M28103
Insert 2 fresh AA alkaline batteries
M28101
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.
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RTH7400/RTH7500 Series
69-2222ES—05