Grundfos ALPHA2 32-40 180

The ALPHA2 32-40 180 is a specialized circulator pump designed for applications requiring high flow rates but low head pressure. With a maximum head of just 4 metres (40 kPa) but a generous 32mm connection size and 180mm flange-to-flange distance, this pump excels in underfloor heating systems, large radiant panels, and hot water recirculation loops where system resistance is minimal but flow volume is critical. Unlike standard 25-40 pumps, the larger 32mm ports reduce friction loss, allowing more water to move with less energy.

Key Benefits

• Low Head (4m / 40 kPa): Perfect for underfloor heating and low-resistance systems – prevents uncomfortable “water hammer” or noise.

• High Flow Capacity (6 m³/h): Despite low head, the 32mm ports deliver substantial flow volume for large zones.

• Up to 85% Energy Savings: Consumes as little as 5 Watts – dramatically lower than older fixed-speed pumps.

• AUTOADAPT Technology: Automatically matches pump performance to system demand without manual adjustment.

• 180mm Flange Distance: Direct replacement for older 180mm circulators in low-head applications.

• Ultra-Quiet Operation: <43 dB – essential for noise-sensitive underfloor systems.

Performance Details
The ALPHA2 32-40 180 delivers a maximum head of 4 metres (40 kPa) and a maximum flow rate of 6 m³/h. Operating modes include:

• AUTOADAPT: Automatically selects optimal pressure curve – ideal for mixed systems.

• Constant Pressure (3 settings): Best for underfloor heating with pressure-dependent manifold valves.

• Proportional Pressure (3 settings): Suitable for radiator systems with low resistance.

• Constant Curve (3 speeds): For system flushing, testing, or backup operation.

The pump includes night setback mode for domestic hot water recirculation, automatically reducing speed during low-demand nighttime hours.

Applications & Usage

• Underfloor heating (wet systems) – Primary application

• Large-area radiant ceiling/panel heating

• Domestic hot water recirculation (large diameter loops)

• Hydronic separation (low-loss headers)

• Chilled water cooling (radiant slab cooling)

• Solar thermal systems (low-pressure collectors)

• Heat pump distribution (low-resistance fan coils)

Why Choose Low Head (4m)?
Many installers mistakenly use high-head pumps (6m or 8m) on underfloor systems. This causes:

• Uncomfortable water noise (velocity too high)

• Increased energy consumption

• Premature valve wear

• Potential manifold damage

The ALPHA2 32-40 180 delivers exactly what underfloor systems need: high flow at low pressure.

Durability & Reliability
Built for continuous operation in demanding environments:

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

• Ceramic bearings & graphite thrust bearing – self-lubricating, wear-resistant

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

• Automatic de-airing function – self-venting during startup

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

• IPX4D rating – splash-proof for mechanical rooms

Customer Value
For NPF Store customers installing or upgrading underfloor heating, the ALPHA2 32-40 180 is the professional’s choice. It delivers exactly the right performance profile – high flow, low pressure – while cutting energy bills by up to 85% compared to older pumps. The 180mm flange distance means it directly replaces many existing circulators without pipe modification. Your underfloor system will be quieter, more comfortable, and far more efficient.

4. Key Features

• ✅ 4m Head (40 kPa) – Optimized for low-resistance underfloor and radiant systems

• ✅ High Flow Capacity (6 m³/h) – 32mm ports deliver maximum volume with minimal friction

• ✅ 180mm Flange Distance – Standard replacement size for older large circulators

• ✅ 32mm Connection Size – Larger ports reduce pressure loss and noise

• ✅ AUTOADAPT Technology – Self-optimizing performance for peak efficiency

• ✅ Energy Class A (EEI ≤ 0.20) – Ultra-low power consumption (5–40W)

• ✅ Night Setback Mode – Automatic reduction for DHW recirculation

• ✅ Automatic Air Purge – Self-venting during installation

• ✅ LED Status Display – Simple color-coded operation monitoring

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

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

5. Technical Specifications