In case of difficulty
The wrong setting is
being changed.
Screen shows "Heat
On" or "Cool On" but
there is no heating or
cooling.
Thermostat does not
respond when a key
is pressed.
Fan does not turn on
when the thermostat
indicates "On."
• Whatever is flashing on the screen is the item that
the up and down buttons affect.
• Call your local heating and/or cooling contractor
to check your system.
• Thermostat is locked. See Locked Keypad
sections.
• If the mode is Unoccupied, the fan control is the
same as with the "Auto" setting. This is true even
when the display indicates "On".
21
53DFS250-HW Thermostat
69-2566EFS—05