Circulation pump GRUNDFOS ALPHA1 25-40 180 220–240V 9H AB0

GRUNDFOS ALPHA1 25-40 180 is a compact circulation pump designed for central heating systems running on 220–240V. The ALPHA1 series offers an energy-efficient single-pump solution for moving heating water through radiator circuits and underfloor heating manifolds. The 25-40 designation indicates compatibility with DN25 connections and a maximum head around 4 m, making this model suitable for small domestic and light commercial installations where reliable, continuous circulation is required.

Advantages

The ALPHA1 25-40 180 delivers stable flow control and quiet operation with low electrical consumption. Its compact wet-rotor design simplifies installation in tight plant rooms and heating cabinets. Built-in features for automatic adaptation to system conditions reduce the need for manual adjustments, and the pump construction supports long service intervals when integrated with properly maintained heating systems.

Suitable for

• Domestic central heating systems with radiator loops
• Underfloor heating manifolds in small to medium-sized homes
• Renovation projects replacing older single-speed circulators
• Light commercial heating circuits with DN25 pipework

When it may not be suitable

This pump is intended for typical hot-water heating systems and may not be suitable where very high head or flow rates are required, such as large commercial plants or industrial process circuits. It is not designed for direct pumping of fluids with high solid content, aggressive chemicals, or for potable water distribution unless specified by the system designer.

Key specifications

• Supply voltage: 220–240 V AC
• Connection size compatibility: DN25
• Maximum head: approximately 4 m (25-40 class)
• Application type: central heating circulation (radiators, underfloor heating)
• Pump design: wet rotor circulator for closed heating systems

How to use

Install the pump in the return or flow line of the heating circuit according to the hydraulic flow direction marked on the pump body. Observe correct alignment and secure flange or threaded connections to avoid leaks. Ensure the electrical connection is carried out by a qualified electrician to the specified 220–240 V supply and protected by appropriate circuit breakers. After installation, bleed air from the heating circuit and check system pressure before starting the pump. Use the pump’s built-in settings to match system characteristics and consult the manufacturer instructions for commissioning and seasonal adjustments.

What to consider before purchase

• Compatibility with existing pipe size (DN25) and flanges or threaded connections
• Required maximum head and flow rate for your heating circuit
• Electrical supply availability at 220–240 V and proper protection
• System water quality and routine maintenance plan

Usage recommendations

For reliable operation, install a suitable strainer and air separator upstream, perform periodic system flushing if needed, and follow the manufacturer’s commissioning steps. Use automatic or manual balancing valves in multi-circuit systems to optimize distribution and reduce noise.