In today's mail, I just got mine.
Instructions said:
1. remove other waterer the night before so when they wake up thirsty in the morning it will be their only choice -- install at 18-inch height or a little lower
2. if the chickens don't catch on rightaway then tap the bottom silver thing so that a few drips will come out --see if they 'get it'
3. if that doesn't work , while they are thirsty, slowly pour water over the top so that it will drip off the bottom, they will go to get the water and self train.
Hope this will help your chickens figure it out.
good luck!