Grundfos MAGNA3 D Twin-Head Variable Speed Circulator Pump

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. This is the twin-head version: two pump heads in one housing for duty/standby, alternating or parallel operation, with the second head ready if the first stops. 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

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.

Each row is one head running. With both heads in parallel the maximum flow rises to about 364 GPM (MAGNA3 D 65-150 GF), 418 GPM (MAGNA3 D 80-100 GF), 387 GPM (MAGNA3 D 100-120 GF).

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.

Commercial heating and chilled water loops, ground-source heat pump systems, radiant floors, air handlers and fan coils, and boiler primary/secondary loops.

From the Grundfos MAGNA data booklet.