ALPHA2 L circulator pump - heating, cooling, hot water



The Grundfos ALPHA2 L is an advanced energy efficient domestic circulator that meets EuP legislative requirements. This makes it an ideal choice for a variety of domestic circulation heating systems.

The ALPHA2 L achieves the highest possible energy savings in comparison to older technology fixed speed pumps. The reduction in power consumption has been achieved by using the latest permanent magnet motor technology and this power consumption can be as low as 5 watts. The variable speed modulating modes allows the pump to match its performance to the system requirements, helping to reduce noise when thermostatic valves are closing down. The ALPHA2 L models are simple to install in new or existing systems, and are 130mm between ports.

Features and benefits

  • Meets EuP legislative demands
  • Energy efficient pump - significant energy savings
  • Variable and fixed speed operation – one pump for all jobs
  • Plug and Pump – no need to open terminal box
  • 5 year warranty

Technical data

  • Liquid Temperature: +2 °C @ 110 °C 
  • Maximum Ambient: 37 °C @ 82 °C Flow
  • Min Inlet Pressure: 1.3m @ 82 °C Flow
  • Maximum System Pressure: 10 Bar
  • Mean Sound Pressure Level: <43 dB(A)

Control of heating systems

The heat requirements of a building vary greatly and today thermostatic radiator valves efficiently control the system output. This can lead to excessive pump pressure and valve noise. ALPHA2 L can not only adapt to these variable conditions but reduce electrical energy consumption.

Fixed speed pump mode

With a fixed speed pump, as the radiator TRV’s close, the system resistance increases causing an increase in pump pressure which can lead to TRV noise.

Pressure controlled mode

As the TRV’s close the pump pressure is controlled according to the selected mode. At the reduced pressure the TRV’s then re-adjust to maintain the required output. The pump pressure reduces radiator valve noise and power consumption.

Installation and operating guidance

When installing the ALPHA2 L, please refer to the Installation and Operating Instructions, if using pump in either constant pressure or proportional pressure mode. *Please refer to the boiler manufacturers minimum flow rate requirements when setting bypass valves.




ALPHA2L data booklet

ALPHA2 L, Model A (Data booklet)

The pump is suitable for clean, thin, non-aggressive and non-explosive liquids, not containing solid particles, fibres or mineral oil. The pump must not be used for the transfer of flammable liquids, such as diesel oil, petrol and similar liquids.

Grundfosliterature-5173525.pdf (6 MB)

Domestic Pump Replacement Guide

Pump Replacement Guide 16/17

for domestic and light commercial circulators and secondary hot water service circulators

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