Grundfos · Commercial Circulator
MAGNA3
16 models, 19-58 ft max head, up to 329 GPM per pump, cast iron housing for closed heating and cooling loops.
Up to 58 ft Head, 329 GPM
ECM Variable Speed, Full Intelligent Control
115-230V 1Ph or 115V 1Ph or 208-230V 1Ph or 230V 1Ph
Cast Iron Housing
Liquid 14 to 230°F
175 psi Working Pressure
Flanged, Grundfos GF Pattern
Composite Rotor Can, Wet Rotor
Overview
The MAGNA3 is Grundfos’s top circulator for commercial heating, cooling, ground-source heat pump and hot water systems. A permanent-magnet motor with an integrated frequency converter runs only as fast as the system needs, and its Energy Efficiency Index is below 0.20, among the lowest on the market. Liquid temperature from 14 to 230°F is independent of ambient temperature (-4 to 104°F).
- AUTOADAPT and FLOWADAPT pick and hold the most efficient proportional-pressure curve on their own
- Constant and proportional pressure, constant curve, constant temperature, differential temperature and constant flow modes, plus FLOWLIMIT and automatic night setback
- TFT display on the pump, Bluetooth to the Grundfos GO app, and built-in heat energy monitoring with an external sensor
- Optional CIM modules for BACnet, Modbus, LON and other building management systems
- Wireless twin-pump pairing for alternating, backup or cascade operation
What Ships and What It Needs to Run
Included: the MAGNA3 circulator with insulating shells; flange gaskets and bolts per Grundfos packaging.
Ships: about 13-75 lb by model.
Needed to run: matching companion flanges (GF pattern; flange kits sold separately), isolation valves, and a 115-230V 1Ph or 115V 1Ph or 208-230V 1Ph or 230V 1Ph circuit with fusing per the manual.
Genuine Grundfos equipment, factory-new in original packaging — sold and supported by Watermain Supply, an independent industrial supplier.
24-Month Grundfos Warranty
Covered for 24 months from the date of installation, but not more than 30 months from the date of manufacture, under Grundfos’s published limited warranty.
Specifications
| Pump type |
Wet-rotor, electronically controlled circulator, in-line flanged |
| Motor |
Permanent-magnet ECM with integrated frequency converter, built-in motor protection |
| Power supply |
115-230V 1Ph, 115V 1Ph, 208-230V 1Ph, 230V 1Ph, 60 Hz |
| Liquid temperature |
14 to 230°F |
| Ambient temperature |
-4 to 104°F |
| Maximum working pressure |
175 psi |
| Pump housing |
Cast iron |
| Connections |
Grundfos GF flanges; port-to-port 6-1/2 to 17-3/4 in by size |
Models & Performance — Will It Do What You Need?
Pick the model whose curve passes through your flow and head. The pump runs anywhere under its top curve, and AUTOADAPT or a set curve holds the duty point.
| Model |
Max head (ft) |
Max flow (GPM) |
At 20% flow |
At 50% flow |
At 75% flow |
| MAGNA3 32-60 GF |
19 |
44 |
8.8 GPM: 19 ft |
22 GPM: 14 ft |
33 GPM: 8.1 ft |
| MAGNA3 32-100 GF |
32 |
54 |
11 GPM: 32 ft |
27 GPM: 20 ft |
41 GPM: 11 ft |
| MAGNA3 32-120 GF |
39 |
54 |
11 GPM: 39 ft |
27 GPM: 22 ft |
41 GPM: 11 ft |
| MAGNA3 40-80 GF |
26 |
90 |
18 GPM: 26 ft |
45 GPM: 19 ft |
68 GPM: 11 ft |
| MAGNA3 40-120 GF |
39 |
113 |
23 GPM: 39 ft |
56 GPM: 25 ft |
85 GPM: 14 ft |
| MAGNA3 40-180 GF |
58 |
126 |
25 GPM: 50 ft |
63 GPM: 30 ft |
94 GPM: 16 ft |
| MAGNA3 50-80 GF |
26 |
133 |
27 GPM: 25 ft |
66 GPM: 16 ft |
99 GPM: 9.7 ft |
| MAGNA3 50-120 GF |
39 |
161 |
32 GPM: 34 ft |
80 GPM: 22 ft |
120 GPM: 12 ft |
| MAGNA3 50-150 GF |
48 |
174 |
35 GPM: 39 ft |
87 GPM: 25 ft |
130 GPM: 14 ft |
| MAGNA3 50-180 GF |
56 |
186 |
37 GPM: 45 ft |
93 GPM: 29 ft |
139 GPM: 16 ft |
| MAGNA3 65-120 GF |
39 |
212 |
42 GPM: 37 ft |
106 GPM: 24 ft |
159 GPM: 14 ft |
| MAGNA3 65-150 GF |
49 |
273 |
55 GPM: 49 ft |
137 GPM: 37 ft |
205 GPM: 21 ft |
| MAGNA3 80-100 GF |
32 |
274 |
55 GPM: 32 ft |
137 GPM: 26 ft |
206 GPM: 14 ft |
| MAGNA3 100-120 GF |
39 |
329 |
66 GPM: 39 ft |
164 GPM: 33 ft |
247 GPM: 18 ft |
| MAGNA3 32-120 F |
39 |
95 |
19 GPM: 39 ft |
48 GPM: 24 ft |
71 GPM: 13 ft |
| MAGNA3 40-80 F |
26 |
91 |
18 GPM: 26 ft |
46 GPM: 19 ft |
68 GPM: 11 ft |
Top-speed (or maximum) curve read from the Grundfos Product Center 60 Hz curve for each model, at 20%, 50% and 75% of that curve’s maximum flow; head in feet of water. The full curve set is the variant image. PSI = feet ÷ 2.31.
Before You Buy — The Limits That Decide the Fit
| Liquid |
Clean, thin, non-aggressive liquids without solids or fibers: water, water-glycol up to 50% |
| Installation |
Horizontal motor shaft; control box not facing down; isolation valves on both sides |
| Inlet pressure |
Keep minimum inlet pressure per the manual to avoid cavitation at high liquid temperature |
| Power |
115-230V 1Ph, 115V 1Ph, 208-230V 1Ph, 230V 1Ph |
Applications
Commercial heating and chilled water loops, ground-source heat pump systems, radiant floors, air handlers and fan coils, and boiler primary/secondary loops.
Materials of Construction
| Pump housing |
Cast iron |
| Impeller |
Composite (PES) |
| Shaft |
Ceramic |
| Rotor can |
Composite |
| Bearings |
Carbon / ceramic |
From the Grundfos MAGNA data booklet.
