18 OPERATION 69-0653-6
Replace the batteries
As the batteries run low, your thermostat shows the following in the digital display:
a. Make sure that the System switch is set in the OFF position.
b. Open the battery door.
c. Press on the left side of the batteries to remove them.
d. Install the new batteries.
Make sure that the positive and negative terminals are oriented correctly as marked inside the battery case.
Note: If you insert the new batteries within 20–30 seconds of removing the old ones, you will not have to reprogram
the thermostat. However, if the display is blank, the batteries are dead or incorrectly installed and you will have to
reprogram. See page 12 to begin reprogramming.
e. Close the battery door and set the System switch to HEAT or COOL.
Note: If “bAt Lo” continues to display after replacing the batteries, set the System switch to OFF, insert the batteries
backwards, wait for five to ten seconds, and return the batteries to their correct orientation. Then see page 12 to begin
reprogramming.
System Cool The thermostat controls your air conditioning system.
Off Both the heating and air conditioning systems are off.
Heat The thermostat controls your heating system.
If you see: Batteries are: You should:
Flashing “bAt Lo”Low Replace the batteries as soon as possible, wit hin the month.
Steady “bAt Lo”Almost dead Replace the batteries immediately. Your heating/cooling system is not operating.
Blank display Dead Replace the batteries immediately. Your heating/cooling system is not operating.
Switch Setting Result
IMPORTANT: Replace the batteries once a year to prevent the heating/cooling system from shutting down due to lack of
battery power in the thermostat. If you are leaving home for longer than a month, change the batteries before leaving to
prevent the system from shutting down due to lack of power.