Grundfos MAGNA3 Circulator Pumps

Grundfos MAGNA3 Circulator Pumps for Commercial HVAC, Hydronic Heating, Cooling, and Domestic Hot Water Systems

Grundfos MAGNA3 Circulator Pumps are intelligent, high-efficiency variable-speed circulators designed for commercial HVAC, hydronic heating and cooling, domestic hot water recirculation, and other building-service applications. Combining an electronically commutated permanent-magnet motor, integrated frequency control, sensors, and advanced pump controls, MAGNA3 circulators can automatically adapt their performance to changing system demand.

The MAGNA3 uses a wet-rotor design in which the pump and motor form an integrated unit without a conventional shaft seal. This construction supports quiet, maintenance-free operation while the electronically controlled motor adjusts pump speed to provide the flow and head required by the system. Grundfos offers MAGNA3 in single- and twin-head configurations, with cast-iron and stainless-steel versions available for different applications.

A key feature of Grundfos MAGNA3 is AUTOADAPT. In this control mode, the circulator continuously evaluates system operation and automatically adjusts its proportional-pressure curve to find a more efficient operating point without compromising system requirements. This makes MAGNA3 particularly useful in variable-flow hydronic systems where control valves open and close as heating or cooling loads change.

MAGNA3 also includes FLOWADAPT, which combines AUTOADAPT with the FLOWLIMIT function. This allows the circulator to adapt its pressure performance while limiting maximum flow through the system. Depending on system design, this functionality can reduce the need for a separate pump throttling valve and help simplify hydronic balancing.

Beyond pump control, MAGNA3 provides integrated system monitoring and connectivity. Available functionality includes a built-in differential-pressure and temperature sensor, heat energy monitoring, operating logs, Grundfos GO connectivity, and communication options for building management system integration. These capabilities make MAGNA3 a strong choice for modern commercial HVAC systems where energy efficiency, commissioning, monitoring, and system optimization are priorities.

Features

• High-efficiency variable-speed circulator pump design
• Wet-rotor construction for quiet, maintenance-free operation
• Electronically commutated permanent-magnet motor technology
• Integrated variable-speed drive and pump controls
• Built-in differential-pressure and temperature sensor
• AUTOADAPT automatically optimizes pump operation according to system demand
• FLOWADAPT combines AUTOADAPT with FLOWLIMIT
• FLOWLIMIT allows maximum system flow to be controlled
• Proportional-pressure control
• Constant-pressure control
• Constant-temperature control
• Differential-temperature control
• Constant-curve operation
• Maximum and minimum curve operation
• Automatic night setback
• Built-in heat energy monitoring
• Operating logs support system analysis and optimization
• Grundfos GO connectivity for setup, adjustment, and monitoring
• Building management system integration available through compatible communication modules
• Multipump functionality for compatible installations
• Single-head and twin-head configurations available
• Cast-iron and stainless-steel configurations available
• Suitable for heating and cooling liquid temperatures from -10°C to 110°C
• Maximum head up to 18 meters depending on model
• Single-head MAGNA3 models provide maximum flow up to 78.5 m³/h
• Designed for maximum system pressure up to 16 bar
• No external motor protection required
• Designed to reduce pumping energy consumption in variable-demand systems

Applications

• Commercial HVAC systems
• Hydronic heating systems
• Hydronic cooling systems
• Chilled water circulation
• Commercial air-conditioning systems
• Domestic hot water recirculation
• Boiler systems
• Radiant heating systems
• Variable-flow hydronic systems
• Two-pipe heating systems
• Heating and cooling distribution loops
• Ground-source heat pump systems
• Solar heating systems
• Snow-melt systems
• Heat exchanger circulation
• Central plant circulation
• Commercial mechanical rooms
• Institutional buildings
• Hospitals and healthcare facilities
• Hotels and hospitality facilities
• Schools and universities
• Office buildings
• Building management system integrated HVAC applications
• Energy-efficiency and circulator replacement projects