Honeywell CT3355A1003 Owner's Manual - Page 9

indicator eventually stops flashing. bAt Lo stays on without flashing, indicating the thermostat and heating/cooling system have stopped working when the batteries are almost completely dead. After the batteries are completely dead, the bAt Lo indicator disappears, leaving a completely blank display. INSTALL TWO AA ALKALINE BATTERIES AS SHOWN M1713 Press down on the left ends of the batteries to remove. If you insert the new batteries within 20 to 30 seconds of removing the old ones, you do not have to reprogram the thermostat. However, if the display is blank, the batteries are dead or incorrectly installed and you must reprogram. See pages 14 and 15 to reprogram. IMPORTANT Although the thermostat has a low battery indicator, replace the batteries once a year to prevent the thermostat and heating/cooling system from shutting down due to lack of battery power. As a precaution, when leaving home for longer than a month, change batteries before you leave to prevent the system from shutting down due to lack of battery power. 9 69-1012