Circulator pump Termojet AUTO energy-saving APE 25/80/180 mm

Circulating pump Termojet AUTO APE 25/80/180 mm — an energy-saving pump with an ECM permanent-magnet motor and wet rotor for heating systems with high circuit hydraulic resistance. Installation length 180 mm, threaded connection 1″ BSP (internal thread of union nut), power consumption 5–65 W, maximum head 8 m. The choice for buildings with a branched pipework network, long underfloor heating circuits, or multiple floors.

Technical Specifications

Operating Modes

Constant differential pressure — Δp-c. The pump maintains the set pressure difference between the supply and return pipe regardless of the number of open valves. The standard choice for radiator systems with thermostatic valves — the pump does not exceed the set pressure when valves close, but instead reduces its speed.

Proportional differential pressure — Δp-v. When the flow rate decreases, the differential pressure decreases proportionally. The mode is optimal for underfloor heating systems and mixed circuits: less noise in the pipes, lower electricity consumption at partial load.

Why the ECM Motor is More Economical

A head of 8 m means this pump is designed for circuits with higher hydraulic resistance. In such systems, the ECM class is especially important: a traditional 3-speed pump running at high speed would consume 80–100 W continuously. The ECM motor regulates speed smoothly — and consumes exactly as much as needed at any given moment. At minimum load, consumption drops to 5 W. The wet rotor requires no maintenance: the heating fluid directly cools and lubricates the rotor, with no shaft seals or lubrication.

Applications

• Buildings over 200 m² with a branched radiator network and increased hydraulic resistance.
• Underfloor heating systems with long circuits (greater resistance of flexible pipe requires higher head).
• Pump groups for underfloor heating with a 180 mm installation length: NG-48 (180 mm) and NG-47 (180 mm).
• Replacement of 180 mm pumps in existing systems where the previous model lacked sufficient head.

APE 25/80 and a Heat Pump System

A heat pump produces heating fluid at 30–55 °C, and this temperature range is ideal for underfloor heating. In branched systems with long circuits where a head of more than 6 m is required, APE 25/80 delivers the necessary pressure without excess. The ECM consumption class minimises the pump’s impact on the overall efficiency of the heat pump system. More details — on the Termojet heat pumps page.

Advantages:

• consumption 5–65 W versus a constant 80–100 W for a 3-speed pump;
• head 8 m — for more complex systems with higher hydraulic resistance;
• wet rotor — no technical maintenance whatsoever;
• installation length 180 mm and 1″ BSP connection — drop-in replacement without pipework modification.

Frequently Asked Questions

When to choose APE 25/80 instead of APE 25/60?
If the hydraulic calculation shows that the circuit resistance exceeds 6 m w.c. — or if the system already has an 8 m pump and you need an equivalent replacement. A head of 6 m is sufficient for most buildings up to 200 m²; 8 m is for branched systems or long floor circuits.

Is APE 25/80/180 compatible with Termojet 180 mm pump groups?
Yes. The pump is compatible with pump groups NG-48 and NG-47. The installation length of 180 mm and the 1″ BSP connection conform to the standard of these groups.