In a mixing bowl, whisk together the flour and the eggs. Gradually add the milk and water. Stir until well combined. Add the salt and butter; beat until smooth. Allow batter to rest for a minute or two.
Heat a lightly oiled griddle or pan over medium-high heat. Pour or scoop the batter onto the griddle, using approximately 1/4 cup for each crepe. Tilt the pan with a circular motion so that the batter coats the surface evenly.
Cook the crepe for about 2 minutes, until the bottom is light brown. Loosen with a spatula, turn and cook the other side.