It can also be the issue of descaling. I clean the filter, the boiler as indicated in the manual. But after 1 year (!gasp) the machine won't deliver expresso anymore. I found that it is suggested to descale every 200 brews! So I descaled the machine and it's back, working. Here's what I did. Don't load any filter. Take a container below the boiler. Plug the machine. Fill the water tank with 50% white vinegar and mix with 50% of tap water. Turn the knob for the red light, wait for the OK green light and turn to the most right option (the one that you usually make espresso with) Wait for hot water to drip, do this during the green lights for 1/4 of the water tank. From time to time, turn the top frothing knob and let the descaler go through. Repeat for another 3 times, and then do the steps again with a second tank with 25% white vinegar and 75% tap water. Finally, load a full tank of tap water to the tank. This is to wash off the descaler from steps mentioned above. Load another tank of water if the acid...