How much water is left over in the boiler probably has a lot to do with how often you would want to change it. With the sight glass indicating Lusso needs water added, there is still a good quart of water sitting at the bottom of the boiler. And since the machine weighs around 30 pounds, siphoning is a good method for emptying this machine.

I've never emptied the boiler except during maintenance and haven't noticed any effect on either the equipment or the coffee. Since my current machine weighs close to 150 lbs and doesn't have a drain I'm really hoping no one can prove I should.