Alpha2 15-55F Variable Speed Circulator Pump w/ IFC, 1/16 HP, 115V


Brand: Grundfos

Mfr Part#: 99163903

Model: Alpha2 15-55F

Availability: In Stock
Usually ships: within 1 business day
Qty Price
$168.95 / each & Free Shipping
x2 $329.90 & Free Shipping
(2 x $164.95 / each)
  • Description
  • Literature
  • Reviews (1)
  • FAQs (1)

Alpha2 15-55F model is a cast iron variable speed circulator with AutoADAPT feature, designed for use in a variety of hydronic and radiant heating applications.
Note: this model replaces older Alpha model 59896877.
Grundfos: UP15-10F, UP15-42F, UPS15-58FC
Taco: 005-F2-2, 007-F5, 008-F6, 00R-MSF, 0015-MSF3
B&G: NRF-22, NRF-9F/LW
Armstrong: Astro 230CI, Astro 250CI, Astro 20, Astro 25, Astro 30
WILO: Star S 16F, Star S 21F, Star S 21RFC, Stratos ECO 16 RFC.


  • New and improved version of Grundfos bestselling Alpha circulator;
  • AutoADAPT feature allows the circulator to adapt to changes in the hydronci system to maximize energy savings;
  • Push button allows to select between AutoADAPT, constant speed (3 settings - Hi/Med/Low) or contant pressure (3 settings) modes;
  • Large LED display;
  • Built-in check valve;
  • Insulation jacket and (2) gaskets (O-rings) included;
  • Permanent magnet motor technology with robust startup enables pump to restart indefinitely when rotor is blocked;
  • Cast iron body for closed-loop heating applications;
  • Standard flange accepts Grundfos GF15/26 and other brand flanges;
  • Hardwire model;
  • Made in the USA.

Technical Specifications:

  • Voltage: 115V;
  • Amperage: 0.65A;
  • Hertz: 60;
  • Phase: 1;
  • Watts: 5 - 45W (depending on mode selected);
  • Wiring: Hardwired;
  • Temperature Range: 36°F - 230°F;
  • Max Pressure: 150 psi;
  • Flow range: 0 - 21 GPM;
  • Head Range: 0 - 19 ft of head;
  • Material: Cast Iron;
  • Application: Heating only.


1 year from the date of installation
Alpha2 15-55F Variable Speed Circulator Pump w/ IFC, 1/16 HP, 115V has an average 5.0 out of 5 rating based on 1 user review.
2 of 3 people found this review helpful.
High Tec pump
By MFParker (from Wayne, NJ) on 1/25/2014
I guess the days of the basic circulator pump are gone. I like bells and whistles and this pump has them all. Easy install. After that the fun starts. This pump has seven modes. Three based on watts, three based on gph and an auto adapt mode. On auto adapt it will alternately display power use in watts and gph being pumped through the system. It's fun to watch. Seems to run fine. I have three pumps/zones active and one inactive connected to a Taco 4 zone controller. I would recommend this pump based on based on the five months they have been in service.
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what diameter piping does this pump need entering and exiting the pump, 3/4, 1" ?
Read 1 answer
2 of 2 people found this answer helpful.
All flanged circulator pumps have a flange outlet, which can accommodate piping sizes from 3/4" to 1-1/4" (1/2" and 1-1/2" on select models) when used together with pump flanges. For Grundfos cast iron circulators, these are:
3/4": Part# 519601 1": Part# 519602 1-1/4": Part# 519603
Answered on 10/19/2015 by PexUniverse Customer Service
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