Before we jump into this. Ask yourself this question. How long do you wait for your shower to “heat up” before getting in? For me, it’s about 3 to 5 minutes. For some reason the kitchen sink takes longer to heat up. But my point is that, most of us, that have a standard water heater with no re-circulation system, it takes a while for the hot water get to where we want it. So, you may have heard about tankless systems, heck even considered it.