About Your New Thermostat; System Setup - Honeywell RTH6400 Series Quick Installation Manual

System setup

About your new thermostat

Press and hold the
changes (approximately 5 seconds).
Press or
s t
Function
1
Done
Press DONE to exit
and save settings.
and FAN buttons until the screen
s
to change settings.
Setting
0
Next
Press NEXT to advance
to next function.
M28349
13 69-2210EF—03
RTH6400
M28348