I own three Whisperflo that I purchased as "remanufactured" pumps from a local company that is no longer in business.
The pumps have been working just fine, but I have some suspicions that the company may have taken some shortcuts when refurbishing.
When I recently went to do a pump service and replace all gaskets, I noticed two of the matching pumps have different sized impellers!
I purchased 1x 0.75 HP and 2x 2 HP Impellers.
Whisperflo sells a "1.5-2HP" impeller, which makes me think the reason the two pumps differ, relates to one of the "2HP" pumps being the *same motor* as the other, but having a "1.5-2HP" impeller.
The short version is...
I have three impellers, their cavity openings are roughly:
1/8" .... 7/32" ... 9/32"
Is there any site where it mentions the dimensions of the Whisperflo impellers? Or does anyone have any idea? I'm guessing they are 0.75, 1.5, and 2.0 HP, but I'd like to be sure before I order a second impeller to match.
Related topic: Increase Impeller on 2-Speed pump
Regarding the smallest pump, this is a two-speed pump that I intended to run at half-RPM.
This is an AO Smith B981 (3/4 HP x 1.67 SF = 1.25 SHP) with either a 0.75 or 1.0 HP Impeller (the 1/8" impeller mentioned above, not sure of the HP/model).
Problem is, once I wired it to run at half-speed, it didn't move enough GPM for my heater's flow-switch.
Considering this is a 1.25 SHP pump, would it be okay to go with a 1.5 HP impeller (WFE-6) at the *slow* 1725 RPM speed only? My goal is improving GPM without wasting power by running at full 3450 RPM.
Thank you in advance for any thoughts or ideas!!