If you want to avoid maintenance completely, some manufacturers offer models that are made in such a way as to easily replace the parts that suffer the most. It is a cheap and efficient option, and something you do just once each couple of months.
You are free to choose your water supplier when you change your water installation from bottled water to direct piping water Singapore. Bonus is that you prefer a model that fits in your space office or home. The water coolers from independent desks can fit between any table, desk, corner or furniture without water supply pipe and can get out of the place.