Dual Water Heater Temp Settings


OK, here's a real simple (aka dumb) question.
We have two identical residential side-by-side (80 gallon?) gas hot water heaters located in the basement. Both were installed together and are about 3 years old. They are connected in series. There is a (passive) recirculation loop connected betweent both tanks and somewhere on the thidr floor.
What is the recommended temp DIFFERENCE setting for this setup? Say tank #1 gets the input cold water from the street and tank #2 supplies the hot water to the house.
#1 temp higher than #2 ? #2 temp higher than #1 ? both temp set the same ?
Some considerations are:
A. operating costs B. tank life time C. recirculation loop operation
There are only two people in our house so recovery is a lesser issue.
A plumber once said to set tank #1 (the street tank) temperature lower than tank #2 to get a longer life time from tank #1.
Recommendations ????
Dennis
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snipped-for-privacy@charter.net wrote:

Turn the gas off to unit #1. Keep as a spare.
Jim
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Yeah disconnect one tank, its way overkill.......
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snipped-for-privacy@aol.com wrote:

Hmmm.... I kinda like the idea of the two water heaters. I'm thinking that one is designed to be set at a higher temp than the other so that the passive recirc loop keeps moving all the time. This way the 3rd floor doesn't have to draw ambient temp water until the pipes empty out and the water from the HWH tank actually starts flowing.
Of course, this setup ALSO causes more heat loss as the pipes in the walls are probably uninsulated, so you pays your money and you takes your pick.
nate
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I think the OP might have meant 2 40 gallon units for 80 gallons total.
snipped-for-privacy@aol.com wrote:

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Personally, I'd re-plumb it so the loop only goes to the second tank, and turn off the first. With two people, one gas heater should be all you need most of the time. Having two heated doubles the heat loss that you have to burn gas to replace. If you have a lot of company, you could still light the first tank.
Bob
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