Grundfos UPS43-100F Replacement

Verified specifications

FC = flow check: the built-in check valve stops gravity circulation through the loop. All three speeds are selectable on the motor terminal box — match the old pump's speed setting when replacing.

ECM upgrade path: Grundfos ALPHA variable-speed ECM circulators drop into the same flanged footprint and cut power draw to a fraction of the 3-speed models.

The VersaFlo: replaces order number 52722363. Head/flow figures follow the Grundfos catalog; one distributor lists lower numbers (53 GPM / 22 ft) — we quote from the catalog curves.

Confirming the right replacement

Before we quote, compare these fields on your failed pump's nameplate. If any of them differ, send us a photo of the nameplate and we'll match it exactly rather than guessing:

• Full model number — including the part number (e.g. B&G P/N) where one exists
• Voltage and phase
• System duty: flow (GPM), head (ft), and fluid — heating water vs. potable water matters
• Flange size and orientation for in-line replacements

Other Grundfos models

• More Grundfos modelsBrowse every Grundfos model page we quote
• Grundfos UPS15-58FC1/25 HP 3-speed circulator, built-in flow check
• Grundfos UPS26-99FC1/6 HP 3-speed circulator, built-in flow check

Documented equivalent replacements

The motors below are published as replacements for this model in the cross-reference tables cited. We confirm the match against your nameplate before quoting:

Cross references via Grundfos-published cross reference documents (VersaFlo UPS/TP guide L-UP-TL-008 and the competitive 3-speed pump cross reference). Match flange size, head, and flow to your system before ordering.