I've only had one house w/ a hot water recirc pump. It was located
right at the water heater & plumbed into the water heater drain port.
I didn't do the installation, it was "professionally" done whne the
house was built
It was a Grundfo, as far as I know they're somewhat pricey but the one
I had ran 24/7 for the 13 years I owned the place with no problems.
here's a link to a pretty good supplier
the pump in the photo looks just like mine. the install shown has a
timer AND a thermostat..............mine just ran all the time
The site has a general installationscheme but maybe you can ask them
about your special sitiation. IMO the far left hand point of the
sketch looks like the right place for your pump, if you can easily put
pumps work best at (near) the low point of the loop (my w/h was the low
ideally, the sensor for the thermostat should be at the hot water
second choice would at the water returning to the w/h
the return water should be dumped into either the drain port? (as was
done in my install) but my gut tells me it makes better sense to dump
it back via the cold water inlet (a check valve might be a good idea)
but it probably doens't make much difference since my old install
my pump was very low powered, you don't need much plus you want to keep
the electrical cost low.
wrt to pump specs, since it's a closed loop you really don't need much
hp, you're just overcoming the friction losses due to flow
I'd ask them what pump they sugggest, you'll just need to know the loop
length, tube material & sizes.
Do you want those Wirsbo tables?