If the buttons on your 45i are not working: 

The 45i has a child safety lock. Do you have the LOCK button enabled? When it is locked, a light will appear above the lock button.

To unlock the control panel: Press and hold the LOCK button for 3 seconds. (You will hear a beep and the light above the LOCK button should turn off.)

If the BreatheSmart 45i control panel is not locked and the control panel is unresponsive, proceed with the following:

1. Unplug the purifier from the wall outlet.
2. Remove the panel and the filter from the purifier.
3. Let the purifier rest for 30 seconds without the filter or panel installed.
4. Reinstall the filter, making sure that it is placed securely back in the unit (insert bottom of the filter first, and then press the top in until it clicks. Then proceed to press on all four corners to ensure that it is completely locked in place.)
5. Place the panel back on the unit, making sure it closes tightly.
6. Plug the purifier back into the wall.
7. Press the power button to power on the purifier.