Why cant I get my control buttons to work properly?
The control buttons are touchy, so its best to lightly tap them with your finger rather than pressing down hard, as that may prevent them from working properly.
How do I measure this dehumidifier as 21 Pints?
The "21 pint" rating refers to the amount of water the unit can produce at 95°F/90%RH in a 24-hour period, not the volume of the water tank. If you are using a hose drain, the size of any internal tank is not a concern.