Circulator pump Termojet AUTO energy-saving APE 25/40/180 mm

Termojet AUTO APE 25/40/180 mm circulating pump — an energy-saving pump with an ECM motor (electronically commutated permanent-magnet motor) and wet rotor for closed hydronic heating systems and underfloor heating. Installation length 180 mm, threaded connection 1″ internal thread, power consumption 5–25 W — thanks to the built-in frequency converter the pump smoothly reduces speed along with system demand and consumes exactly as much electricity as needed at any moment.

Technical Specifications

Operating Modes

Constant differential pressure — Δp-c. The pump maintains a set pressure difference between the supply and return lines regardless of how many thermostatic valves are open. Standard choice for radiator heating: the system remains balanced even when most rooms have warmed up and the valves have closed.

Proportional differential pressure — Δp-v. The differential pressure decreases proportionally with the reduction in flow rate. When underfloor heating circuits partially close, the pump automatically reduces pressure and speed — less noise, less electricity consumption. Δp-v mode is recommended for underfloor heating systems and mixed schemes.

Applications

• Radiator heating in a private house (gas, solid-fuel or electric boiler).
• Underfloor heating via a pump group or manifold — installation length 180 mm is suitable for replacing old 180 mm standard pumps without reworking the pipework. For installation in pump group NG-48 (180 mm) or NG-47 (180 mm).
• Replacement of a worn 3-speed pump with installation length 180 mm and 1″ thread — connection without adapters.
• Heat pump systems: ECM-class consumption minimises additional electricity costs when paired with an HP.

Why an ECM Motor Is More Cost-Effective

A conventional 3-speed pump consumes 80–100 W continuously — regardless of the actual load. The APE 25/40 consumes only 5–25 W: the permanent-magnet ECM motor with frequency converter smoothly regulates speed to match the system's current demand. Over a heating season the difference in the electricity bill is tangible.

Wet-rotor technology: the rotor is submerged in the heat-transfer fluid — the liquid cools and lubricates the rotor without shaft seals or external lubrication. No scheduled maintenance throughout the entire service life, quiet operation.

• Consumption 5–25 W versus 80–100 W for a conventional 3-speed pump.
• Wet rotor — no maintenance required.
• Installation length 180 mm and 1″ internal thread — drop-in replacement without reworking pipework.
• Ukrainian manufacture: no customs delays, fast service, official warranty.

For Heat Pump Systems

A heat pump produces heat-transfer fluid at 30–55 °C — the ideal range for underfloor heating and low-temperature radiators. Every extra watt from the circulation pump reduces the real COP of the system. The APE 25/40 in Δp-v mode automatically adapts to the varying load of the heat pump — minimum consumption at partial HP output. More about compatible equipment — Termojet heat pumps.

Frequently Asked Questions

Why can 4 m head be sufficient?
Hmax 4 m covers compact heating systems up to 100–150 m² with standard pipework. For underfloor heating with short circuits and low hydraulic resistance — it is sufficient. If the system has long circuits or a complex distribution unit — consider the APE 25/60 model with 6 m head.

Is the pump suitable for 180 mm pump groups?
Yes. Installation length 180 mm and 1″ internal thread are the standard for Termojet NG-48 and NG-47 pump groups. View Termojet pump groups.