single_digit
New Member
I have a bit of an unconventional dilemma. I have an older gas Takagi tankless HW heater in my upstairs. It has had issues for years and I've concluded that the gas line does not deliver sufficient volume under high demand. So I need to replace it. When I did some other plumbing work years ago I added a HW line that could be run from my basement Rinnai tankless to the upstairs. However, it's a long circuit and would take quite a while to deliver hot water to the upstairs bathroom. Further I didn't plumb in for a recirculating loop. To solve my issues I was thinking I could have had a small gas tank heater where the Takagi was. I would then run hot water from the basement tankless heater up to the small tank heater with the idea that initially I deplete the tank while hot water comes in from the basement to recharge it. Note that I don't have room for a large tank heater upstairs and I don't think I can deliver sufficient gas (long run with several turns on 3/4 line to supply a large tankless heater. Is my proposed solution going to create unforeseen problems for me?