hot water recirculation loop

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...

We recently moved into our house and have an issue with what appears to be a dedicated hot water recirculation loop. When the recirc pump is running, our cold water isn't cold. When the pump was plugged in and running 24x7, you could let the cold water run for 10 minutes and it still wouldn't...