Circulating pump WITA Delta HE light 40-25-180

Product detailed description

This pump is suitable for residential and commercial heating systems, including underfloor heating, radiant panels and low-temperature circuits. It replaces standard circulation pumps in systems where variable flow control and energy efficiency are required. Installers working on modern heat pump systems or condensing boiler circuits will find this pump suitable for maintaining stable differential pressure or constant flow.

The compact design allows for installation in tight spaces such as mechanical rooms, under sinks or behind wall panels. The pump supports both constant speed and proportional pressure control modes, making it adaptable to different system layouts. Its IP42 rating ensures protection against splashing water, suitable for indoor environments. The pump can handle media temperatures up to +110°C, supporting integration into high-efficiency condensing systems.

Technical parameters

Code	DHEL0001HW
Brand	WITA

The maximum head of 4.0 m and flow rate of 2800 l/h define its suitability for small to medium heating systems. The energy consumption ranges between 3 W and 23 W, depending on load. The IP42 rating means it is protected against solid objects larger than 1 mm and splashing water. These parameters are critical for sizing the pump to match the system’s hydraulic requirements and for ensuring long-term reliability in fluctuating conditions.

Installation and connection

Installers should ensure the pump is mounted on a rigid pipe section with vibration-damping supports to prevent mechanical stress. The pump connects via DN 15 to DN 32 ports using threaded or flanged fittings, depending on the selected model. The installation length varies from 110 mm to 180 mm, accommodating different pipe layouts. The body is made of grey cast iron with a cathodic coating for corrosion resistance, except for the 110 mm variant, which uses brass. Key checkpoints include verifying the electrical supply (230 V, 50 Hz) and ensuring the motor is not overloaded. Common errors include incorrect mounting orientation, which can lead to cavitation, and failure to secure the pump properly, causing vibration-induced leaks. The anti-block function prevents dry running, but the system must still be primed correctly before operation.

Compatibility and accessories

This pump is compatible with most standard heating systems that require variable flow or constant pressure control. It integrates well with thermostatic valves, room controllers and building management systems via its programmable settings. For complete installation, additional items such as thermal insulation jackets, sealing rings and mounting brackets may be required, depending on the system layout. No specific accessories are listed as mandatory in the product description.

Technical background for designers

The pump operates using a permanent magnet EC motor, which provides higher efficiency compared to conventional AC motors. The body material—grey cast iron with a cathodic coating—ensures durability in aggressive environments. The pump’s ability to maintain either constant speed or variable differential pressure makes it suitable for both simple and complex systems. Long-term performance is influenced by the quality of the installation, the presence of air in the system and the stability of the power supply. The motor’s built-in protection eliminates the need for external safeguards, simplifying system design.

Service and operation

Routine maintenance includes checking for blockages, verifying the integrity of seals and ensuring the motor remains free of dust. The anti-block function reduces the risk of mechanical damage due to dry running, but regular visual inspections are recommended. The pump does not require scheduled service intervals, but any unusual noise or drop in performance should trigger an inspection. The EEI (Energy Efficiency Index) of ≤ 0.18 indicates it meets high-efficiency standards for heating applications.

Frequently asked questions

Can the pump operate in condensing systems?
Yes, it is suitable for systems with media temperatures up to +110°C, including those with condensation cycles.

Is the pump compatible with programmable room controllers?
Yes, the eight selectable performance curves allow it to adapt to different control strategies, including those from room thermostats.

Can the pump be mounted vertically?
Yes, provided the inlet and outlet ports are aligned correctly and the pump is secured to prevent vibration.

Does the pump require an external motor protector?
No, the motor has integrated protection, eliminating the need for external components.