Price "guess" Tankless Water Heater/10 Gallon storage and existing recirc pump
Hi! I am a homeowner finishing up a new home abandonded midway by the builder in Arizona. He previously installed a recirculating pump on a big water heater, but while the checkbook is out, it seemed the right time to look into doing it "right".
The layout: 5500 sf house, 5 bathrooms. The utility room has the front loading washer and is the center of a triangle between between Leg A) 30 feet to the kids' jack and jill tub/shower and 60 feet to another a guest shower Leg B) 60 feet to the master w/ big ol' whirlpool tub, dual head shower with body bar and Leg C) 75 feet to the kitchen and 130 feet to one upstairs guest shower. Who knows how the original builder's plumber ran all the lines in a loop? I'm just saying there is a lot of pipe in them thar walls!
My plumber is suggesting a Rinnai 9.4 GPM attached to a 10 gallon "feeder/storage" tank, on which the existing recirculating pump will be installed. I guess the idea is that the small tank will only turn on the tankless heater when it recirculates enough to drop the temperature? I have a 500 gallon propane tank with feeding this closet where the magic will happen.
I want to make sure I'm not burning through the propane or wasting water trying to get hot water to the kitchen sink, nor do I care to run out of hot water while sandblasting my cares away in the shower with that body bar. Two adults will use the master, and two little kids are there half-time.
Can anyone tell me some pros and cons of doing it this way? What approximately should the whole thing cost, the unused tank heater is already out, the pipes are there, the gas line is there, etc.
I get confused when you go online and you can get the water heater itself for $1,100 or so, and his bid is $3,000. I've been really happy with his work on all the other fixtures he has installed...