Canpipe Limited


Circulating Pumps


The new ALPHA2 takes reliability in small domestic circulators to new heights. Even in systems where the operational environment is a challenge, the ALPHA2 will ensure long-lasting trouble-free operation with no risk of blockage.

ALPHA2 is versatile and efficient whether you use one of its seven speed, pressure control settings, or simply leave it on the factory setting AUTOADAPT™.

The ECM motor design reduces energy consumption by 50%, and in AUTOADAPT™ mode, will automatically analyze the heating system, find the optimum setting, continue to adjust its operation to changes in demand, and reduce power consumption by up to 85%. This to ensure the lowest possible energy consumption without sacrificing comfort.

Key Features and Benefits:
  • Simple push button
  • Control enables the ALPHA2 to be programmed in one of 3-constant speed
  • 3-constant pressure, or AUTOADAPT™ control modes. The current operating mode is always visible on the ALPHA2’s LED display
  • The large LED display shows the current energy consumption in Watts and estimated flow in gallons per minute
  • For installation, you have the flexibility to use either our unique ALPHA Plug with line cord or the ALPHA2 with terminal box for conduit connections
  • ALPHA2 is complete with an integrated check-valve, foam insulation jacket, and nut captures for flanges. 
  • ALPHA2 comes in both cast iron and stainless steel models
  • Robust startup enables the ALPHA2 to continuously attempt to restart – indefinitely – in blocked rotor conditions
  • ALPHA2 can be used as a replacement for more than 30 competitor pump models
  • ALPHA2 materials and design resist blockage from magnetite and iron oxide particles found in closed hydronic systems. 

The ALPHA2 is suitable for:
  • Systems with constant or varying flow
  • One pipe systems
  • Two pipe systems
  • Underfloor-heating
  • Domestic hot-water recirculation
  • Systems where night setback is required


Grundfos circulators are specifically designed for heating and cooling systems. The wet rotor design ensures quiet maintenance free operation. Our 3-Speed models allow you the ability to adjust the pump speed to fit your specific application.


Specifically designed for heating and cooling in residential and commercial applications.

Heating Systems:
  • Boiler/Hydronic heating
  • Ground-source heat pumps
  • Radiant floor heating
  • Hydronic and fan-coil heating
Domestic Hot-Water Systems:
  • Solar water heating
  • Hot-water recirculation
  • Domestic hot-water heating
Cooling Systems:
  • Chilled water pumping 
Features and Benefits:
  • Easy to install
  • Maintenance free
  • Quiet operation
  • Wet rotor design
  • Integral check valve – selected models
  • Single, 3-Speed, and Variable-speed models available
  • Cast iron, Lead free Bronze, or NSF 61 Stainless Steel options
  • Terminal box or Line cord models

Open Systems

Grundfos Bronze and Stainless Steel circulating pumps are used for hot water recirculation and open systems because these materials are not effected by air and oxygen released into these types of systems through the constant introduction of fresh water. They’re made for whisper quiet operation for sound sensitive conditions. These pumps are of the canned-rotor type, i.e. pump and motor form an integral unit without shaft seal and with only two gaskets for sealing which helps to extend pump life by keeping foreign debris out. The bearings are lubricated by the pumped liquid.

The maximum temperature of liquids to be used with these pumps will vary by pump and the maximum liquid temperature will be directly affected by the ambient or surrounding air temperature around the pump. If a UP pump is equipped with a timer, then the maximum allowable liquid temperature is 150°F (66°C). The Grundfos UP and UPS pump types 25, 26, 43, and 50, can be used with chilled water because their motor construction is suitable for temperatures as low as 32°F (0°C) as long as the pump housings are compatible with the pumped liquids.

3-speed pumps are adjusted manually by the user to the preferred speed as needed offering more flow rate flexibility than single speed pumps. Speed adjustment should not be done while pumps are in operation.

Variable speed and mixing-reset control pumps are used to customize heating systems to increase user comfort. Variable speed pumps can be set for variable speed operation or can be set manually to operate at one speed. The motor output can be set to run at a variable speed by either voltage or current. The motor output is set by adjusting 4 switches (called “dip switches”) located on the pump, in a predetermined sequence by the manufacturer, to control by Voltage: 0-10V(DC) or 2-10V(DC); Current: 0-20mA or 4-20 mA.

These pumps are excellent for open solar heating systems, domestic hot water recirculation, and circulation of liquid in cooling and air conditioning systems. Grundfos bronze and stainless steel pumps are manufactured for use with potable or non-potable water, softened water or with a 50/50 mixture of water and propylene glycol. These pumps can be installed in both horizontal or vertical piping installations.

For a new recirculation system setup, you will need a flange or union adapter set, which are sold, to properly install your pump. If you are replacing an old Grundfos recirculating pump, you may not need new adapters.

Closed Systems

These Grundfos circulating pumps operate whisper quiet for sound sensitive applications. 3-speed pumps offer more flow rate flexibility than single speed pumps and are manually adjusted to the preferred speed by the user as needed. Speed adjustment of 3-speed pumps should not be done while the pump is in operation.

The UP and UPS series pumps are a canned rotor type. The motor and the pump are made as an integral unit without the need of a shaft seal and only two gaskets are used for sealing. The pump has a ceramic shaft and radial bearings with a carbon thrust bearing. The bearings are lubricated by the pumped liquid. Pumps housings are made in cast iron, bronze or stainless steel for use in appropriate liquids and water conditions. The impellers are made of a durable, corrosion resistant, PES (30% glass filled).

The maximum allowable liquid temperature of these pumps are determined by the ambient or surrounding air temperature around the pump. If any UP pump is equipped with a timer, the maximum liquid temperature is 150° F (66° C) even if the pump specifications show a higher temperature. The UP and UPS 25, 26, and 43 pump types can be used with chilled water due to their motor construction, which is suitable for 32° F (0° C) as long as the pump housings are compatible with the pumped liquids.

Cast iron pumps are excellent for use in radiant heating systems, hydronic baseboard or floor heating systems, fan coil heating systems, heat recovery/heat pump systems, geothermal heating systems, closed solar heating systems, air conditioning systems and other chilled water applications.

Grundfos cast iron pumps are intended for use in closed systems with potable or non-potable water, softened water or with a 50/50 mixture of water and propylene glycol. If water conditions exist that are not compatible with cast iron, then Grundfos recommends the use of a bronze or stainless steel pump. These can be installed in both vertical and horizontal lines.