What to Know Before Buying a Water Cooler or Dispenser
Make sure the water has a hechsher.
Are you asking what you need to know?
Is it worth the cost? What size do you need? How often are you going to replace the water bottle? Do you drink enough to get a monthly contract with a water delivery service?
Do you need a cooler, or just a room temperature dispenser? If you get a cooler, do you want a hot water button as well?
Will there be kids using it? (See above hot water question, though they have a basic safety feature). Will they be spilling water on a floor or carpet?
Are you giving advice that you forgot to include, or are you asking a question that was just not clearly worded?
1) How much it costs.
2) How you are planning on paying for it.
3) Where you will be getting water to keep it filled with.
4) They use a lot of electricity (like a mini-fridge.)
5) Pick a style and design that has features you like.
6) If you are Jewish, the dispenser lever/buttons, temperature controls, and overall system should be Shabbos-compatible.
7) You need a place to put it that is very close to an Outlet, and should not have carpeting or expensive wood flooring that might get ruined by spilled water.
And so much more. You should study the sugya for at least six months before making such a major life commitment!