Circulator pump Termojet AUTO energy-saving APM 25/8/180 mm

Termojet AUTO APM 25/8/180 mm circulator pump — a high-performance energy-saving circulator with an ECM permanent-magnet motor and wet rotor for heating systems with elevated flow-rate requirements. Installation length 180 mm, pump body thread G1½″, threaded connection Rp 1″ BSP (female union nut), power consumption 5–80 W, maximum head 8 m, flow rate up to 8 m³/h.

Technical Specifications

AUTO Operating Modes

Constant differential pressure (Δp-c). The pump maintains a set pressure difference between the supply and return pipes constantly, regardless of the number of open valves. Δp-c mode is a reliable choice for radiator systems with a large number of emitters and thermostatic valves on each one.

Proportional differential pressure (Δp-v). The differential pressure decreases together with the flow rate at partial system load. Δp-v mode minimises noise and consumption — optimal for mixed systems (radiators + underfloor heating) and for pump groups with a mixing valve.

Applications

• Large radiator systems in buildings from 200 m², where high flow rate (up to 8 m³/h) is required at moderate head.
• Pump group NG-51.150 (180 mm) — for this group a pump with a G2″ body is required: the APM 32/8 is suitable.
• Pump group NG-52.150 (180 mm) — likewise a pump with a G2″ body is required: APM 32/8.
• Replacement of an old 3-speed pump with G1½″ body thread and installation length 180 mm — without modifying the pipework.
• Heat-pump system with a multi-zone manifold: Termojet heat pumps.

Why ECM Is Better Than 3-Speed

An old asynchronous DN25 pump consumes 80–120 W at any of its three fixed speeds — even in the off-season. The ECM motor of the APM 25/8 regulates speed smoothly from minimum to maximum: 5 W in base mode, 80 W at peak flow. Wet-rotor technology: the heat-transfer fluid cools and lubricates the rotor without shaft seals or external lubrication. The pump requires no maintenance throughout its entire service life.

APM 25/8 and a Heat-Pump System

The high flow rate of up to 8 m³/h allows the APM 25/8 to serve a manifold with multiple underfloor heating zones connected to a heat pump. Δp-v mode provides automatic adaptation to the variable load of the heat pump without water hammer. See comprehensive solutions at tjheatpump.com.ua.

Frequently Asked Questions

Why APM 25/8 and not APE 25/80 with the same 8 m head?
The APM 25/8 has a significantly higher flow rate — up to 8 m³/h versus 3.6 m³/h for the APE 25/80.

Can the APM 25/8 be installed instead of another manufacturer's DN25 pump?
Yes. The installation length of 180 mm and the Rp 1″ BSP connection are the standard for pumps of this class. Installation requires no adapters and no pipe modification. Also see the Termojet pump group catalogue.