Hot water recirculation pump confusion

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My house has a dedicated return line and I want to get a recirculation pump but between head, horsepower and flow rate... I'm lost.

At first I had my mind made up to get the Grundfos AutoAdapt UP 10-16 pump (https://product-selection.grundfos....-north-america/grundfos-comfort-north-america) because I like that it learns your usage habits and adapts to them. But with just 3.9ft max head it seems underpowered. Even though I have read several times that head doesn't matter, the Grundfos materials suggest it does. In one place they say that this pump is for homes up to 2,000 sqft and in another they say it's for "a footprint of up-to 2,000 square ft." This is splitting hairs but if my home is 2 stories and 3,600 combined, is my "footprint" under 2,000? Probably not.

As I said, the house is 3,600 sqft on two stories. The recirculation line was here when I bought the house so I have no idea how long it is, how many branches, how many elbows, etc. The house was built before there was such a thing as PEX so all I know is that the line is not PEX.

How do I know what pump to buy? Should I just get a multi-speed pump so I can adjust if necessary? I can do that but I'd rather not because they seem to be about triple the price too. Even if I can get away with it, I am starting to lean away from that Grundfos above and towards a traditional pump with a Smart Recirculation Control (

Any advice?

John Gayewski

In the Trades
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What kind of pipe do you have?

What is the longest distance the water will travel in this loop? Meaning how many feet of pipe.

Also need the size
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