I'm looking into installing a new tankless water heater for my entire home. I have a 200 amp service, and the unit I'm looking at is 28kw. Would it be better for me to install the 4 30amp two pole breakers that the manufacturer specs. Or should I run a 120 amp into sub panel and then to the 4 breakers. It seems to me that using a subpanel will be more expensive, but a cleaner way to do it. Any suggestions? And what does anyone think of the tankless solution?