Your Kontessa espresso pot is a piece of coffee-brewing art. It should be under glass in a museum, but in your case, the Kontessa espresso pot is on your kitchen counter. The least you can do is treat it like the classic coffee brewer it is.
To maintain your Kontessa espresso pot, wash all of its parts with hot soapy water after each use. Make sure to clean the gaskets, too, on a regular basis. That way, the gaskets could last as long as a year. Use a dull knife, or small screwdriver, to take out the gasket. Anytime you see that your gasket is dried or cracked, it’s time to replace it. You can also tell that you need a replacement gasket when some steam escapes from in between the top and bottom pieces of your machine. You can order replacement gaskets right from Kontessa.
The overpressure plug on your Kontessa espresso pot, on the other hand, should last many years. Of course, you need to take care of it to enjoy it for this long. Do not press down hard on the coffee grounds when tamping them. Instead, smooth the coffee, lightly knocking the funnel downwards to help even out the grounds. This plug is a safety mechanism to open the way for steam to escape when you over tamp coffee grounds.
When applying heat to your Kontessa espresso pot, make sure to keep it low. Place it directly under the pot, which will help you from getting bluish discoloration on your Kontessa. Especially with smaller Kontessa models, keep the handle away from the heat source, no matter if the machine isn’t perfectly centered on the heat. You can even try a diffuser. It will limit heat exposure.
You may not be able to avoid all discoloration on the inside and on the outside of your Kontessa espresso pot. This is normal and unavoidable. Repetitive heating and minerals in your water supply will do that to it. Your goal is to limit it as much as possible, as well as get rid of the heat spots as soon as they appear. You can clean some with silver polish.