Circulator pump Termojet AUTO energy-saving APM 25/12/180 mm

Termojet AUTO APM 25/12/180 mm circulating pump — a powerful energy-saving pump with an ECM permanent-magnet motor and wet rotor for large heating systems. Installation length 180 mm, threaded connection 1¼″ BSP (internal thread of union nut), power consumption 5–180 W, maximum head 12 m, maximum flow rate 10 m³/h. Designed for boiler rooms of large residential buildings, commercial and industrial facilities, and systems with elevated head and flow requirements.

Technical Specifications

Operating Modes

Constant differential pressure — Δp-c. The pump maintains the set pressure differential between the supply and return regardless of flow rate. This mode is suitable for radiator systems with a large number of thermostatic valves: when some of them close, the pump does not build excess pressure but smoothly reduces speed.

Proportional differential pressure — Δp-v. The differential pressure decreases proportionally with the flow rate. The optimal choice for large underfloor heating systems and combined circuits: at partial load the pump significantly reduces consumption from the maximum 180 W down to minimum values.

Why the ECM Motor Is More Cost-Effective in Large Systems

In large heating systems, a conventional pump of this class would consume several hundred watts continuously. The ECM motor of the APM 25/12 smoothly adapts its speed to the actual load: at minimum flow, consumption drops to 5 W; at maximum — to 180 W. The wet rotor (the heat-transfer fluid directly cools and lubricates the rotor) eliminates the need for maintenance throughout the entire service life. No shaft seals, no wearing parts, quiet operation.

Applications

• Boiler rooms of large private residences (from 300–500 m²) and small commercial facilities.
• Heating systems with elevated hydraulic resistance: multiple floors, long piping runs, balancing valves.
• Pump groups for underfloor heating with 180 mm installation length: NG-51.150 (180 mm) and NG-52.150 (180 mm).
• Replacement of uncontrolled large-size pumps with transition to ECM class.

APM 25/12 and Heat Pump Systems

In large systems with a heat pump, where the heat pump serves an extensive underfloor heating network on multiple floors, the APM 25/12 provides the necessary head and flow rate. The Δp-v mode allows the pump to automatically reduce load in sync with the reduction of the heat pump's output. For more information about heat pumps and comprehensive solutions, visit the Termojet heat pumps page.

Advantages:

• head 12 m and flow rate 10 m³/h — for large and complex systems;
• ECM motor: from 5 to 180 W depending on load;
• wet rotor — zero maintenance;
• 1¼″ BSP connection, 180 mm installation length.

Frequently Asked Questions

How does APM differ from APE?
The APM series offers greater head (up to 12 m vs. 6–8 m for APE) and higher flow rate (up to 10 m³/h vs. 3,2–3,6 m³/h). APM is designed for large systems; APE is for standard homes up to 200–300 m². The APM 25/12 connection is 1¼″ BSP.

Is the APM 25/12 compatible with 180 mm pump groups?
Yes, the 180 mm installation length and 1¼″ BSP connection ensure compatibility with pump groups NG-51.150 and NG-52.150. Before installation, verify the thread match of the group.