White Rodgers 1F90-51 Operation Manual page 31

To change your clock, follow the instruc-
tions for setting current time and day. See
ENTERING YOUR PROGRAM. Thermo-
stat programming is not affected when you
change the clock.
14. Do I have to reprogram my thermostat
after I change the batteries?
When the thermostat is on the wall and the
system has power, the thermostat is being
powered by a 24 VAC source. If power is
lost, or if the thermostat is removed from the
wall, the program will be retained for ap-
proximately one minute if there are no
batteries installed or if the installed batteries
are dead. If you are changing the batteries
after seeing a flashing BATTERY on the
display, the installed batteries may be dead.
If you remove the old batteries and install
fresh ones within one minute, you should
not lose your thermostat programming. Af-
ter installing new batteries, follow the proce-
dures in CHECK YOUR PROGRAMMING
to determine whether your programming
was maintained. If the thermostat maintains
programming, press
displayed, put the thermostat back on the
SYSTEM
wall, press
SWITCH
mode you want, then press
program operation. If the program is lost,
reprogram the thermostat. See PROGRAM-
MING YOUR THERMOSTAT.
SYSTEM
until OFF is
SWITCH
to select the operating
RUN
to start
PRGM
31