It seem to me that for a lot of coffee enthusiasts, after a periods of enjoying coffee whether it is drip brewed, french pressed or in moka pots, there will be a certain point where they want to acquire an espresso machine to have the ability to make espresso at home. It was certainly true for me as I started out enjoying coffee with a french press, then a moka pot, then moving to a vacumn pot and eventually jump to espresso machine. I think that it would be good to discuss the issue of machine maintainance when it comes to espresso machine.
Unlike other method of enjoying coffee, espresso preparation require rather complicated machinery to properly extract and make the espresso; that is because espresso require water to be at the correct temperature and pressure. Because of this complicateness, once the espresso machine break down, it require some knowledge to get it up and running again. But when it comes to espresso machine, things tend to go wrong quite often and for a variety of reasons. For intance, just the act of heating water will cause deposit of scale on the metalic surface of the espresso machine boiler and group head and overtime will cause problem with the ability of the espresso machine to brew coffee. Preventive measures such as using soften water and making sure that to clean up after making shots will go a long way to prevent machine problem but eventually problem will happen. I believe that it is therefore nescessary for the coffee enthusiast to have some knowledge with the espresso machine so that when they encounter problem, they at least should know how to get it up and running again because espresso machine repair services are rather expensive especially if a shop is not located near where you live which means it could be difficult to ship the machine out for repair services.
There are not a lot of thing that could actually goes wrong with espresso machine and a lot of problems are related to the problem of scale build up. Therefore, I believe that every espresso machine owner should know how to descale their machine (my favorite descaling agent is citric acid). Also, seals in espresso machines will degrade overtime and eventually cause leakage; it is the espresso machine owner's job to be obsevant and notice any symptom of water leak and replace the seals early to prevent big and expensive electronic damages. Also, there is a huge database of knowlege on various coffee forum for many different machines that can guide owners toward solving their problems with their machines.