How Do Drip Filter Coffee Machines Work? If you're unfamiliar with this particular coffee maker, you could be surprised to find it has a lot of parts. It starts with a reservoir that has an air tube that leads to it, and a heating element inside that warms the water. https://wwwcoffeeeuk19160.livebloggs.com/36679042/what-s-holding-back-in-the-drip-coffee-industry