WILO Circulation Pump Atmos Pico 25/1-4 180 High-Efficiency Wet-Rotor Pump

With an Energy Efficiency Index of ≤ 0.20, the WILO Atmos Pico 25/1-4 180 sets a benchmark in low-energy circulation for heating, air conditioning, and industrial systems. This high-efficiency wet-rotor pump delivers a maximum head of 4 m while consuming only 4–20 W, thanks to its electronically commutated motor (ECM). The 180 mm installation length and G 1½ connection make it a direct replacement for many standard circulators, while the LED display provides real-time feedback on setpoint, power consumption, and error codes.

Overview

The Atmos Pico 25/1-4 180 is engineered for continuous duty in closed-loop systems. Its grey cast iron housing (EN-GJL-200) withstands pressures up to 10 bar, and the stainless steel shaft with carbon metal-impregnated bearings ensures long service life. The pump operates quietly and reliably across a fluid temperature range of -10 °C to +95 °C, with IPX4D protection against splashing water and insulation class F for thermal endurance.

What stands out

• Ultra-low energy consumption: EEI ≤ 0.20, far below the EU efficiency benchmark.
• Intelligent control modes: variable differential pressure (Δp-v), constant differential pressure (Δp-c), and fixed speed for tailored system balancing.
• Manual de-blocking function: a simple front-access screw allows rotor freeing after long standstill.
• Automatic de-aeration: reduces commissioning time and prevents air locks.
• Integrated motor protection: no external overload relay needed.

Technical details

• Pump type: high-efficiency wet-rotor circulation pump
• Max. head: 4 m
• Nominal connection: G 1½ (DN 25)
• Installation length: 180 mm
• Power consumption: 4–20 W
• Mains connection: 1~230 V, 50/60 Hz
• Protection class: IPX4D
• Insulation class: F
• Max. operating pressure: 10 bar (1 MPa)
• Fluid temperature range: -10 °C to +95 °C
• Housing material: grey cast iron (EN-GJL-200)
• Impeller material: plastic (PP-GF40)
• Shaft material: stainless steel
• Bearing material: carbon, metal impregnated
• Motor technology: ECM

Our verdict

The WILO Atmos Pico 25/1-4 180 combines premium efficiency with practical features like manual de-blocking and automatic de-aeration. It is an excellent choice for installers and facility managers seeking a durable, low-maintenance circulator that meets modern energy standards.