We’ve also got a Rinnai system at our house. Works great! If you get one, factor into the cost that you’ll need to do maintenance annually where they descale the unit(s), which is essential for them performing. They’re not as simple as a traditional water heater but well worth it.
We have a Takagi tankless heater. We just replaced our original one a few months ago. The original one lasted close to 15 years I think. If there is maintenance to be done on it, my husband does it. We've never had a service person come out for it - but we do for our furnace, so I know if we needed it, we would do it. Our house is about 2,300sqf and it's been great. Highly recommend.
