it requires 3x 60A breakers I think. Supposedly good for 4.5 gallons continuous but that number assumes something like a 35 degree temp rise. In the winter the ground water is colder so it needs to heat more to get to temp so it can't handle as much flow. I've added a 30 gal water heater kept at very low temp to compensate. The electric ones are nice because they can modulate temperature much better than gas and also start heating quicker. Gas ones can need up to a gallon of water to flow before they will even kick on. My biggest complaint, having kids, is them taking 30+ minute showers all too often.