I have recently purchased a La Spaziale Vivaldi II. At the store, it was suggested that I use a Mavea water filter system for the machine. My plumber put in an Insinkerator filtering system, telling us it was a lot cheaper to buy filters for. But he put in a hot water filter system. Should it matter? Why put in a hot water filter when cold water is required? Feeling kind of silly to ask but no one can give me a straight answer. I'm not concerned about Mavea vs Insinkerator. Just the hot vs cold filter system.