The Grundfos UPML 25-105 180 Circulation Pump, also referenced Nibe 259477, is a component typically used in heating systems, particularly in conjunction with Nibe heat pumps of which are OEM circulator pumps designed for integration into boilers and heating appliances.

Here are some typical specs for this class of pump:

Technical Specifications

• Pump Type: OEM circulator
• Installation Length: 180 mm.
• Thread Size: G40 external.
• Flow Range: Up to approx. 4.5 m³/h depending on system resistance.
• Control Signal: Supports PWM (Pulse Width Modulation) or analog 0–10V input for dynamic speed control.
• Power Supply: 230V, 50/60Hz.
• Energy Efficiency: Compliant with ErP and Eco design regulations.

 Materials & Build

• Pump Housing: Cast iron with corrosion-resistant coating.
• Impeller: Composite material for durability and quiet operation.
• Bearings: Ceramic for long service life and low noise.

Compatible with a range of Nibe heating systems, especially those in the Fighter, F-series, and S-series lines. While the exact model "25-102" isn't widely listed, it's closely related to the UPML 25-105 180, which is designed for integration into high-performance boilers and heat pumps.

These pumps are generally used in:

• Ground source heat pumps like the Nibe F1145, F1155, F1245, F1255, F1330 & other GSHP models.