Aaron FIsher wrote:
On Mon, 14 Mar 2011 17:31:28 -0400, Tony Miklos wrote:
Which is it? Series or parallel? Or do you want to go from parallel to
series?

My mistake for not being clear.

They are clearly in series.

The well pumps the cold water which goes to a four-foot high blue steel
bladder tank which goes to the first 50 gallon hot water heater which
goes to the second 50 gallon hot water heater in series which somehow
goes to a hot-water recirculation motor about the size of a small bench
grinder motor ... which goes to the bathrooms, laundry room, and kitchen.

My question is why (I'm slowly learning why) and what to set the
temperature at (since it's currently set the same for both at about 130
degrees or so).
I have seen the tandem system used only once, by a co-worker.
He had a big unit, working on night-current only(very cheap in our
country), and a small unit after it, using day- and night-current.
The small unit would quickly heat(big heating element), and would be fed
with cooler water later in the day.
That combi had a rather constant water temperature for a
reasonable price.
Thermostats were the same on both machines.