This thing is awesome....endless hot water is a necessity with two teenage girls. I've had it for 10 years and it still keeps working, however I bought a second just in case (and because there is a $300 Federal tax credit applicable for 2021). For those new to this, you will need to also buy valves for input and output so that you can flush the unit to remove any mineral buildup. You will also need a cheap pump (total prob an additional $150). Need to run white vinegar through the unit about twice a year to remove mineral buildup...takes about an hour. The only complaint here that prevents 5 stars is that the unit will flash a digital code that means you need to flush/clean the unit....but Rheem doesn't give consumers access to clear the code. They want you to spend money on Rheem maintenance I suppose. There is a way to do it but you have to remove the cover and press some buttons in the right way on the circuit panel. The flash code is an annoyance that never goes away if you don't clear it but the unit will still operate fine. In hindsight, I would check and see if the manufacturer provides codes AND a way to clear them from the digital panel without having to open the unit.