Adding a tankless water heater

[maxdad118]

So I knew the hot water would be an issue when we added a large jacuzzi bath tub to our added master bedroom. I work for the gas utility and know about gas volumes and preferred dedicated lines for tankless systems. My question is can I leave my 40 gallon tank connected and plumb a tankless in between the 2 bathrooms? The 40 gallon is on the other side of the house. What would determine which heater supplies the hot water? I want to leave it as a backup if the tankless is down for whatever reason and vice versa.

 

[Snoonyb]

If you are looking for "instant gratification", as the end result, unless you include a recirc. system there will still be a delay.

I think I would install a timer controlled recirc. for the existing.

 

[maxdad118]

It’s not about the instant feature but the quantity or endless hot water that I’m looking for.

 

[Snoonyb]

Then you need to weight the cost benefit of installing and on-demand, or an 80gal.