2 50 Gal Tanks with return line plumbed between the two

[Boofuss]

We have 2 50 gal LP tanks connected in series. There is a return line (recirculating line? loop line? not sure what to call it) coming back which connects between the 2 tanks as shown. The tanks are 22 years old and I want to replace them. I don't want tankless, just want to replace what we have. The house is 5 bedrooms and so the capacity is important, but only my wife and I live here. I only want the larger capacity for when we might sell the house. So I don't think we need to continually recirculate hot water -- just not enough usage to justify the energy use. So we always leave the pump unplugged and close the gate valve below it. It is true that in our master bath upstairs we wait a LONG time (several minutes?) to get hot water. I can't honestly say where the "farthest" point in the house is as plumbed, but much of the house is slow to get hot water. I don't really even care to fix that as we are used to it. I know when I turn on the pump things change for the better.

My question is, is this currently plumbed correctly? I read all about need to plumb the return line BEFORE the first tank. Maybe I should have our plumber change the routine when he replaces the tanks?

 

[Sylvan]

No, it is not plumbed correctly

Ideally, you want an equil draw and piped in series, which is not correct

 

[Sponsor]

 

[Fitter30]

The difference is with a reverse return both tanks get equal flow.

 

[Jeff H Young]

first tank in a series system does almost all the heating but the circ going into second tank might be better to give that tank a chance to work a little more ( although I havent seen this type build nor recomending it because I have no proof its a good way ) . but modern theories favor the reverse return system and drawings on a proper install are available online free from manufactures

 

[Boofuss]

No, it is not plumbed correctly

Ideally, you want an equil draw and piped in series, which is not correct


View attachment 107576

So with this method, where would I hook up the hot water return line?

 

[Master Plumber Mark]

So with this method, where would I hook up the hot water return line?

your original drawing is close to correct for a series install in a home

you would want to hook up the return pump line to the bottom drain of the first heater in series
so the low temp water has to flow through both heaters---

Series is the only way I ever hook up heaters.....in a residential situation
if one ever fails its no big deal to install some other brand back in series again and
it does not affect the flow

you cant do that and expect it to flow properly in
parallel, it will always fails you at some point