Grundfos ALPHA2 GO 25-90 180 Circulator Pump

The Grundfos ALPHA2 GO 25-90 180 circulator pump, reference 93074208, is a high-efficiency electronic circulator designed for heating and HVAC installations. It offers a maximum head of 9 meters, a nominal flow rate of 2.7 m³/h, and a modulating electrical power consumption of just 3 to 90 W. Its G 1½" threaded connection, 180 mm installation length, and advanced control functions make it a particularly versatile solution for both new installations and the replacement of existing circulators.

The ALPHA2 GO also stands out for its connectivity with the Grundfos GO app via Bluetooth. From the app, the installer can perform guided commissioning, select the control mode and setpoint, view operating data, access the event history, carry out hydraulic balancing, and use the pump’s diagnostic tools.

Electronic circulator pump with a maximum head of 9 meters

The Grundfos ALPHA2 GO 25-90 is designed for installations that require greater hydraulic capacity within the range of domestic and light commercial circulators.

Reference 93074208 offers a maximum head of 9 m. Its nominal operating point is approximately 2.7 m³/h flow and 6.14 m head, although the actual operating point will depend on the hydraulic resistance and the control mode selected in each installation.

The integrated electronics adapt motor operation to provide the required flow and pressure, avoiding keeping the pump permanently at maximum speed.

Intelligent AUTOADAPT control

The ALPHA2 GO includes the AUTOADAPT function, developed by Grundfos to automatically adjust the circulator’s operation to the actual thermal demand of the installation.

AUTOADAPT can work with both proportional pressure control and constant pressure control. The pump analyzes operating conditions and progressively selects the most suitable curve within its available range.

Grundfos recommends AUTOADAPT for common applications such as:

• Radiator systems.
• Underfloor heating.

Advanced AUTOADAPT configuration is carried out through the Grundfos GO app.

Different control modes

The ALPHA2 GO allows its hydraulic behavior to be adapted to different types of installation through several control modes.

• Proportional pressure: pressure decreases when flow demand drops and increases when demand rises. It is especially useful in radiator circuits with thermostatic valves.
• Constant pressure: maintains a stable differential pressure regardless of the number of open circuits, making it especially suitable for underfloor heating and manifolds with multiple zones.
• Constant curve: the pump operates according to a fixed selected speed or curve.
• Constant flow: maintains the set flow regardless of pressure variations in the circuit.
• AUTOADAPT: automatically optimizes the operating point according to system needs.
• External PWM control: allows an external controller to modulate the pump via a compatible PWM signal.

Advanced modes and their setpoints can be configured using Grundfos GO.

Bluetooth connectivity with Grundfos GO

The ALPHA2 GO incorporates built-in Bluetooth to communicate directly with the Grundfos GO app from a compatible mobile device.

This connectivity provides the installer with additional tools to configure, diagnose, and document the installation without the need for external communication accessories.

Available functions include:

• Guided setup.
• Control mode selection.
• Setpoint calculation.
• AUTOADAPT configuration.
• Operating data viewing.
• Event and error logging.
• Hydraulic balancing.
• Pump software update.
• Commissioning documentation generation.

Guided setup to simplify commissioning

The guided setup function in Grundfos GO helps the installer select the appropriate control mode and setpoint for the specific characteristics of the circuit.

The app asks a series of questions about the type of installation and, based on this information, suggests a suitable configuration. When AUTOADAPT is not the most appropriate option, Grundfos GO can also help determine the corresponding setpoint.

This function is especially useful during commissioning of new installations and when replacing older circulators.

Designed for circulator replacement

Grundfos has developed the ALPHA GO range with replacement of existing circulators in mind as well.

The Grundfos GO app includes a replacement search function that allows thousands of existing circulator pump models to be identified and the compatible alternative and recommended configuration to be checked.

The ALPHA2 GO is especially intended to replace standalone circulators and different compatible integrated Grundfos pumps from the UPM3 and UPM4 families.

Air detection and venting function

The ALPHA2 GO features an air detection function. When activated through Grundfos GO, the pump can identify the presence of air around the impeller.

When air is detected, it can activate a specific pulsed operation to help move it toward the system’s venting points.

This function facilitates commissioning and can help diagnose circulation problems associated with air in the circuit.

Dry-run protection

The pump includes protection against dry running. If it detects that it is operating without sufficient liquid, it can stop to protect the unit and display the corresponding alarm.

Grundfos GO allows error codes and event history to be checked to help identify and resolve the issue.

Robust start

The ALPHA GO range includes a robust start function. If the rotor encounters resistance or the pump becomes blocked, the motor makes new starting attempts using high torque to try to restore operation.

This feature is especially useful after long periods of system inactivity.

Data and diagnostics via the app

The ALPHA2 GO can provide various operating data through Grundfos GO, making system diagnostics easier.

Parameters that can be analyzed include:

• Estimated flow.
• Head or pressure delivered.
• Power consumption.
• Water temperature.
• Operating time.
• Events, warnings, and alarms.

The historical log helps the installer identify abnormal behavior and check system performance over time.

Hydraulic balancing with Grundfos GO

The ALPHA2 GO includes hydraulic balancing functions through the Grundfos GO app.

Proper balancing of an installation helps distribute flow correctly between emitters and circuits, preventing some zones from receiving excess water while others have insufficient flow.

This feature is especially useful in heating systems with multiple radiators or underfloor heating circuits.

High energy efficiency

The pump incorporates a high-efficiency electronic motor and integrated frequency converter. Reference 93074208 has an energy efficiency index EEI of 0.20.

Electrical power consumption varies between just 3 and 90 W depending on the selected operating point and hydraulic demand.

This modulation helps reduce consumption compared with traditional circulators that maintain fixed speeds regardless of demand.

Single-phase 220-240 V power supply

The Grundfos ALPHA2 GO 25-90 180 operates on a single-phase 220-240 V, 50/60 Hz power supply.

Current consumption is approximately between 0.04 and 0.78 A, depending on operating conditions.

Thermal protection is electronically managed and the motor has insulation class F.

180 mm installation length

The 180 designation of the model corresponds to its 180 mm connection distance, a common size in circulators installed in heating systems.

This feature should be checked together with the connection diameter before replacing an existing pump.

G 1½" connections

The pump incorporates G 1½" threaded hydraulic connections in accordance with ISO 228-1.

The nominal connection pressure is PN 10, matching the pump’s maximum permissible operating pressure.

Maximum working pressure of 10 bar

The ALPHA2 GO 25-90 180 is designed to operate at a maximum system pressure of 10 bar.

It must be installed in hydraulic circuits whose design conditions and safety components ensure this limit is not exceeded.

Liquid temperature from -10 to 95 °C

For reference 93074208, Grundfos specifies a pumped liquid temperature range of -10 to 95 °C.

This allows use in different closed heating and HVAC circuits, provided the fluid, temperature, and the rest of the installation components are compatible.

The permitted ambient operating temperature is between 0 and 55 °C.

Cast iron pump housing

The hydraulic housing is made of EN-GJL-150 cast iron, a common material in circulators intended for closed heating circuits.

The impeller is made of reinforced composite material, helping combine low weight and strength within the hydraulic assembly.

This version is not intended for domestic hot water circulation.

Technical specifications of the Grundfos 93074208

• Brand: Grundfos.
• Range: ALPHA2 GO.
• Model: ALPHA2 GO 25-90 180.
• Reference: 93074208.
• Type: electronic circulator pump.
• Application: heating and HVAC.
• Nominal flow: 2.7 m³/h.
• Nominal head: 6.14 m.
• Maximum head: 9 m.
• Installation length: 180 mm.
• Connections: G 1½".
• Nominal connection pressure: PN 10.
• Maximum operating pressure: 10 bar.
• Liquid temperature: -10 to 95 °C.
• Ambient temperature: 0 to 55 °C.
• Power supply: 1 x 220-240 V.
• Frequency: 50/60 Hz.
• Minimum power input: 3 W.
• Maximum power input: 90 W.
• Current consumption: 0.04-0.78 A.
• Energy efficiency index EEI: 0.20.
• Frequency converter: integrated.
• Thermal protection: electronic.
• Protection rating: IP44.
• Insulation class: F.
• Housing material: EN-GJL-150 cast iron.
• Impeller material: reinforced composite material.
• AUTOADAPT: yes.
• Proportional pressure: yes.
• Constant pressure: yes.
• Constant curve: yes.
• Constant flow: yes.
• External PWM control: yes.
• Bluetooth: integrated.
• Compatible with Grundfos GO: yes.
• Guided setup: yes.
• Air detection and venting: yes.
• Dry-run protection: yes.
• Warning and alarm logging: yes.
• Hydraulic balancing: yes, via Grundfos GO.
• Net weight: approximately 1.93 kg.
• Gross weight: approximately 2.14 kg.
• EAN: 5715467404357.

Smart circulator pump for heating and HVAC

The Grundfos ALPHA2 GO 25-90 180 combines high hydraulic capacity with advanced electronic control and mobile connectivity. Its 9-meter maximum head, modulating power from 3 to 90 W, and different control modes make it suitable for installations with radiators, underfloor heating, and other closed heating and HVAC circuits.

Integration with Grundfos GO adds guided setup, AUTOADAPT, hydraulic balancing, air detection, diagnostics, and data logging, providing the installer with tools for both commissioning and maintenance, as well as for replacing existing circulators.