Grundfos ALPHA2 25-40 130

The ALPHA2 25-40 130 is a premium, energy-efficient low-head circulator pump from Grundfos’ award-winning ALPHA2 series – the world’s most advanced residential circulator. Delivering 4 meters (40 kPa) of head pressure in the industry-standard 130mm flange-to-flange format, this pump is specifically designed for low-resistance heating systems that require gentle circulation without excess pressure. Featuring Grundfos’ intelligent AUTOADAPT technology, the pump automatically learns your system’s characteristics and continuously optimizes performance – no manual speed selection, no guesswork. This is the perfect pump for underfloor heating, radiant slabs, single-story homes, and domestic hot water recirculation.

Key Benefits

• Low Head (4m / 40 kPa): Gentle circulation perfect for underfloor heating and low-resistance systems – prevents uncomfortable water noise and system stress.

• Industry-Standard 130mm Flange: Direct drop-in replacement for thousands of existing pumps – no pipe modification required.

• AUTOADAPT Technology: The pump automatically learns your system and continuously adjusts performance for peak efficiency – set it and forget it.

• Massive Energy Savings: Consumes as little as 5 Watts – up to 85% less energy than older UPS 25-40 or UNO pumps.

• Standard 25mm Connections: Direct fit for residential piping systems (1″ or 1¼” with adapters).

• Alarm Relay Output: Remote fault signaling for integration with home automation systems.

Performance Details
The ALPHA2 25-40 130 delivers a maximum head of 4 meters (40 kPa) and a maximum flow rate of 3.5 m³/h. The pump features multiple operating modes:

Additional features:

• Night setback mode – Automatic speed reduction for DHW recirculation during low-demand hours (2am-5am default)

• LED user interface – Color-coded status and fault indication for easy troubleshooting

• Alarm relay output – Remote fault signaling (volt-free contact)

Why Low Head (4m) is the Right Choice for Many Systems
Not all heating systems need high pressure. Low-head pumps are ideal for:

The Problem with Oversized Pumps:
Many homes have pumps that are too powerful (6m or 8m on systems that only need 4m). This causes:

• ❌ Uncomfortable water noise (rushing/hissing sounds)

• ❌ Increased energy consumption (higher bills)

• ❌ Premature valve and component wear

• ❌ Potential water hammer damage

If your system has noisy pipes or you have a single-story home with underfloor heating, you likely need a 4m pump.

AUTOADAPT Technology Explained
Unlike simple 3-speed pumps where you guess the right setting (and often get it wrong), AUTOADAPT continuously monitors your heating system’s demand:

1. Learning phase (first few days): Pump maps your system’s pressure/flow characteristics

2. Optimization phase: Automatically selects the most efficient pressure curve

3. Continuous adjustment: Responds to changing conditions (zone valves closing, TRVs adjusting, outdoor reset, etc.)

Benefits of AUTOADAPT:

• ✅ No manual speed selection – The pump finds the optimal setting for you

• ✅ Maximum energy savings – Never wastes energy over-pumping (as low as 5W)

• ✅ Reduced system noise – No excess pressure causing water hammer or pipe noise

• ✅ Longer component life – Valves, zone valves, and boiler components see less stress

• ✅ Adapts to seasons – Automatically adjusts for higher demand in winter

ALPHA2 vs ALPHA1 (25-40 130): Which to Choose?

Choose ALPHA2 if: You want maximum energy savings (pays for itself in 12-18 months) and automatic performance optimization.

Applications & Usage

• Underfloor heating (wet systems) – Primary application ⭐

• Single-story homes with radiators – Low-resistance radiator systems

• Small apartments and condos – 1 story, compact systems

• Domestic hot water recirculation – Small-to-medium loops

• Radiant ceiling panels

• Solar thermal systems (low-pressure collectors)

• Heat pump distribution (low-resistance fan coils)

• Chilled water cooling (small systems)

• Replacement for older UPS 25-40 130 pumps – Direct drop-in upgrade

Durability & Reliability
Engineered for continuous operation (24/7/365):

• Stainless steel rotor can (AISI 304) – corrosion-resistant

• Ceramic bearings & graphite thrust bearing – self-lubricating, wear-resistant (50,000+ hours typical life – over 5 years continuous operation)

• Dry-running protection – automatic shutdown if water supply is interrupted

• Automatic de-airing function – self-venting during startup, prevents air lock damage

• Cast iron housing (EN-GJL-200) – durable for decades of service

• IPX4D splash-proof rating – safe for mechanical rooms and boiler rooms

• Alarm relay output – remote fault signaling for home automation integration

Customer Value
For NPF Store customers with underfloor heating, single-story homes, or low-resistance systems, the ALPHA2 25-40 130 is the perfect choice. It directly replaces older UPS 25-40 pumps and thousands of other 130mm flange circulators without pipe modification. The combination of 4m low head (gentle circulation), AUTOADAPT technology (automatic optimization), and massive energy savings (as low as 5W) ensures your system operates quietly and efficiently. With an annual energy cost as low as $8-12, this pump typically pays for itself within 12-18 months. For contractors, the drop-in 130mm flange and alarm relay output make it the professional’s choice for low-resistance system upgrades.

4. Key Features

• ✅ 4m Head (40 kPa) – Gentle circulation optimized for underfloor and low-resistance systems

• ✅ 130mm Flange Distance – Industry standard – direct replacement for most residential pumps

• ✅ Standard 25mm Connections – Direct fit for residential piping systems

• ✅ AUTOADAPT Technology – Self-optimizing performance, no manual tuning needed

• ✅ Energy Class A (EEI ≤ 0.20) – Ultra-low power consumption (5–35W)

• ✅ 85% Energy Savings – Compared to older UPS/UNO pumps

• ✅ Night Setback Mode – Automatic reduction for DHW recirculation

• ✅ Alarm Relay Output – Remote fault signaling for home automation

• ✅ Automatic Air Purge – Self-venting during installation and operation

• ✅ LED Status Display – Color-coded for easy troubleshooting

• ✅ Dry-Running Protection – Prevents damage from water loss

• ✅ Ceramic & Graphite Bearings – Long service life (50,000+ hours)

• ✅ 4 Operating Modes – AUTOADAPT, Constant Pressure, Proportional Pressure, Constant Curve

• ✅ Ultra-Quiet Operation – < 40 dB – virtually silent, ideal for underfloor systems

• ✅ Wet Rotor Design – Self-lubricating, maintenance-free

5. Technical Specifications