Keep your coffee gear clean, all of it!
Today as I found a little time to descale my espresso machine and auto drip, I was thinking about all the coffee machines and two cheap espresso machines that my parents tossed because they broke. The reality is my parents live in an area with extremely hard water and scale builds up fast when machines are heating water inside of them. Since my parents never descaled their machines, the scale eventually I am assuming killed these machines, which is why my parents have only bought twenty dollar machines for the past 20 years or so.
Source: http://www.roaste.com/CoffeeBlogs/intrepid510/Keep-your-coffee-gear-clean-all-it