WPL 24 I

  • Made in Germany
  • Air source hydronic heating heat pump for indoor installation
  • Ideal for retrofits due to constantly high flow temperatures
  • Highest energy efficiency rating – captures and reuses any wasted heat from the inverter
  • Quietest air source solution for greater comfort
  • Smart Grid ready to connect to solar PV as well as home energy management systems
  • Optional ISG web allows control and monitoring of heat pump remotely
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Product Overview

The WPL 24 I air source hydronic heat pump from STIEBEL ELTRON has been engineered specifically for indoor installations. The unit provides high-temperature flow-rates up to 65°C to allow for both in-slab and radiator heating. Innovative technology such as a modulating fan control and advanced vapour injection guarantees unbeatable efficiency.

Product Details

Being installed indoors, the WPL 24 I remains extremely quiet thanks to its encapsulated refrigerant circuit, acoustically isolated compressor and wide-gap evaporator fins. The WPL 24 I can be used with optional STIEBEL accessories such as the ISG web unit which allows for control and monitoring of the heat pump remotely from your mobile device.

STIEBEL quality for your indoor hydronic heat pump
  • German made hydronic heat pump for indoor installation
  • Up to 65°C flow temperatures for use with in-slab and radiator hydronic heating
  • Perfect for hydronic heating in retrofits
  • Optional ISG web unit allows for comprehensive after sales support
Advanced technology from Germany
  • Modulating fan control and wide evaporator fins to keep operating sound to a minimum
  • Smart Grid ready to connect to a home energy management and solar PV system
  • Consistently high flow temperatures thanks to advanced inverter technology

Technical Data

Model Number WPL 24 I
Energy efficiency class A++
Rated voltage 400 V (3 phase)
Output at A7/W35 (EN14511) 15.7 kW
Coefficient of performance at A7/W35 (EN14511) 4.72
Sound power level (EN 12102) 49 dB(A)
Max. application limit on the heating side 65 °C
Height/Width/Depth (standard appliance) 1116/784/1182 mm
Height/Width/Depth (indoor installation) 1182/800/1240 mm
Weight (appliance) 201 kg
Weight (indoor installation) 289 kg


File Category Type Download
WPL 24 I Operation and InstallationOperation and Installation GuidePDF
27.64 MB
Air Source Hydronic Heat Pump WarrantyWarrantyPDF
113.55 kB
WPL 24 I CAD FileTechnical DrawingDXF
670.47 kB
WPL 24 I Explosion DrawingTechnical DrawingPNG
72.65 kB
WPL 24 I Tech Line DrawingTechnical DrawingPNG
64.32 kB


1. How does a hydronic heat pump work to heat my home?

Air source heat pumps use a refrigeration circuit to harvest energy from the air. This energy is then used to heat the water which is pumped through a hydronic heating circuit, such as in-slab piping or radiators, to warm your home.

2. How noisy is a hydronic heat pump?

Hydronic heat pumps from STIEBEL ELTRON are the quietest on the market thanks to an encapsulated refrigerant circuit and acoustically isolated compressor. Advanced sound engineering guarantees that heat pumps from STIEBEL ELTRON can be used in neighbourhoods with a dense population. Many models even feature an additional silent mode.

3. Can a hydronic heat pump system still heat my home when it is cold outside?

Yes, hydronic heat pumps from STIEBEL ELTRON are engineered to operate energy efficiently even when outside temperatures fall below zero. Advanced technology from Germany ensures efficiency even at cold temperatures down to -20°C. For instance, the natural defrost function of the WPL 25 AC(S) comes into play in temperatures around 0°C to ensure a smooth and efficient operation when it becomes frosty in New Zealand winter.

4. Can I use hydronic radiators with this heat pump?

Yes, STIEBEL ELTON offers a wide range of hydronic heat pumps which serve as heat source for either under floor heating or radiator heating, or both. This depends on the models' flow temperatures. Please consult with a STIEBEL expert to identify the right system for your needs.

5. Where can I purchase a STIEBEL ELTRON hydronic heating heat pump from?

STIEBEL ELTRON is working closely with hydronic heating specialists throughout New Zealand. Feel free to get in touch and ask for a recommended installer.

6. Do I need three phase power to operate a hydronic heating heat pump?

STIEBEL ELTRON offers both single and three phase models. The letter S in the model description stands for single phase, such as the WPL 25 ACS. Please also check the technical details on the product page of your model or contact STIEBEL ELTRON for further advice.

7. Can I control my hydronic heating heat pump from my mobile device?

All STIEBEL ELTRON heat pumps in New Zealand are offered with an optional ISG web, which allows you to control and monitor your heating system via a home network or mobile device.

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