From Tank to Tankless

[ncviswan]

I bought a new house with a 75 gallon tank water heater installed in 2013. Right now it's just my wife, baby, and me so we really don't need such a big tank, but during the holidays we'll have upwards of six additional people visiting. I would like to install a tankless system that I can use for most of my hot water needs and use the existing tank for bigger loads when needed. Is there a way this can be done? So far I've only come across recirculating systems or using the tank as a "buffer" between the tankless heater and the points of use as ideas for incorporating a tank with tankless. Any other suggestions? Obviously I'm trying to be efficient with this setup... Thanks!

 

[havasu]

Are you natural gas or electric?

 

[ncviswan]

Sorry, it's a Natural Gas tank

 

[havasu]

I believe you are overthinking this way too much. On my old house, I installed a Navien T/W/H which has a built in recirc pump and built in buffer tank, and had all the hot water I could ever use for my family of five, including two teenage daughters. Here is how the process works:

https://www.navieninc.com/residential/water-heaters

The downside is you will never have any form of emergency water in an emergency, no power=no hot water, and unless you have an annual maintenance by a certified "specialist" plumber, and have a pre-filter, you will run into constant maintenance.

This current house I installed a typical 50 gal gas water heater, where I won't touch it for another 10-12 years, no maintenance, lots of emergency water, and will have hot water for the next day regardless of if I have power or not.