I have a 3 bath home with just 3 of us living here. My main water line runs into a 30 gal gas unit. It then runs out of the 30 gal unit and into a 50 gal gas unit and then out to the house. There is a line spliced into the outgoing line over to a circulating pump and into the hot water coil at the furnace. It then comes out of the furnace and into the drain valve on the 30 gal unit.
Do I possibly need this much hot water? Both of my units are over 20 years old and I am concerned about their lifespan. I would like to replace both units with a single if possible. Is it really a bigger draw on the water heater since the hot water is circulating through the water coil and right back into the tank?