GRUNDFOS Alpha2 is a revolutionary variable speed controlled circulator pump designed for hot water circulation in heating, cooling and solar applications. The pump is provided with a number of unique features:

  • Variable Speed inverter technology that enables the pump to selectively operate on a constant curve, proportional pressure where pressure is adjusted according to heat demand and constant pressure where pressure remains constant irrespective of system demand.
  • Three selectable speeds so the pump performance can be matched to system requirements.
  • Fully automatic AUTOADAPT function which continuously adjusts pump output to system demand and thus optimises energy consumption.
  • Display indicating power consumption and flow as well as alarm and warning conditions.

Pump construction is cast iron for the pump housing, stainless steel for the rotor can and composite plastic for the impeller. Pumps are supplied complete with BSP union connections and insulating shells.

The pump is fitted with an integral 4-pole synchronous permanent-magnet high efficiency inverter controlled motor fitted with thermal overload protection. The pump should be connected to a suitably rated MCB or fuse.

Enclosure Class: X4D
Insulation Class: F
Voltage: 1x240V

Pumped Liquids: Thin, clean non-aggressive liquids without solid particles or fibres
Liquid Temperature: +2°C to +110°C, though a maximum of +65°C is recommended for optimal system efficiency
Max. Ambient Temperature: +80°C
Max. Operating Pressure: 10Bar
Min Inlet Pressure: Up to +75°C – 0.05 Bar, up to +90°C – 0.3 Bar, up to +110°C – 1 Bar
Installation: Pumps must be installed with the pump shaft horizontal, vertical water flow and the plug connection pointing downwards


Model Motor Dimensions (mm) Weight (kg)
Power(W) Max Current(A) A B C D E H
ALPHA2 25-60 34 0.32 121 89 52 36 104 180 2.1


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