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Lochinvar Knight WHB085 + Taco VR3452-FC1A01 (0-10v input) Boiler Pump

tuffcalc Member Posts: 35
Hi everyone,

Installing a Lochinvar WHB085. All the literature states that it comes with a variable speed ECM boiler pump with 0-10v input (so the Lochinvar can control it's speed) for the primary loop. Unfortunately when the WHB085 arrived it had a standard non-ecm grundfos pump in the box. Called Lochinvar and they told us only the euro versions come with the ECM pump. Anyway, here we are.

I went on a mission to find an ECM pump with 0-10v control input. Looks like the smallest ecm pump I could find that supports 0-10v input from a boiler is a mid-sized Taco VR3452-HB1-FC1A01. The submittal sheet shows a pump curve that needs at least 2 feet of head to pump 1 GPM (https://s3.amazonaws.com/s3.supplyhouse.com/product_files/Taco-VR3452-HB1-FC1A01-Submittal.pdf)

Called Taco to see if the pump would work at those low rates. They said they didn't know.

My alternative is using a standard variable voltage pump like the Taco 007-VVF5, but again, no guarantees from Taco that it will pump at super low GPMs.

Anyone have any suggestions or experience in a similar situation? Should I try the VR3452, or return it and go with the 007-VVF5?