Rinnai’s are by far, the best! I have been installing tank less water heaters for years and Rinnai are the easiest to install, have the best controls, the very best warranty in the business, and service techs and centers all over the US. Some models are even designed to be installed outside, thus no gas in the house and more room for storage. I hope this helps. I would put in nothing else! Kind regards!

Rinnai and Rheem both make very good units. The venting is critical and must be done properly by a certified technician, dealer or plumber.
You will spend about 2 1/2 times for a Tankless than a standard water heater with tank,

According to my source, Rinnai is the highest rated at ***** out of *****.

Rinnai is expensive but very good instant water heater.
There are several others.
The most important “component” is the installing contractor.