Holzminden, GermanyCity area Natural Earth · GeoNames

STIEBEL ELTRON: Heat pumps, hot water and local building integration

STIEBEL ELTRON makes heat pumps and hot-water systems, with ISG gateways providing documented local Modbus TCP integration.

Summary

Best for
Heating projects needing matched heat-pump and controller equipment, with documented ISG integration for supported system combinations.
Less suited to
Assuming an ISG gateway supports every controller generation, or that a temperature, setpoint and measured heat-energy total are interchangeable values.
Deployment
Heat pump and WPM controller on site, with an appropriate ISG gateway connecting the supported system to the local network and service options.
Data in
Modbus TCP system values, parameters, operating states and energy information through compatible ISG/controller combinations.
Pricing
Heat pump, hydraulic equipment, controller, gateway and installation are selected as a complete heating system.

Overview

STIEBEL ELTRON's history begins with Theodor Stiebel's immersion heater in Berlin in 1924. The business later expanded into hot water, heat pumps and ventilation. Its company overview identifies a family-owned group based in Holzminden, where production, administration and the Energy Campus training centre share a location.

The equipment range combines a physical heat source with a heating-system controller. The WPL installation manual describes an air-to-water heat-pump family and the supporting installation. ISG Connect adds the network gateway for compatible heating or ventilation systems. This layered approach is useful for integration: the heat pump, controller and gateway have separate identities, and the documented combination determines the available data. Local network access and optional manufacturer services then sit around the operating heating system.

Offering

The WPL 25 AC product page identifies an air-to-water heat pump and the required WPM controller. The installation manual covers the related WPL A, AC, AS and ACS variants, including equipment installation, electrical connections and system operation. Those product and controller choices form the physical heating package, together with the required hydraulic arrangement.

ISG Connect is the communications gateway between supported heat-pump or ventilation equipment and the home network or internet. Its manual describes local operation and service options, and states that Modbus TCP/IP software is installed on the gateway for compatible systems. The separate Modbus software documentation provides the data tables. The compatibility overview maps equipment families, controllers, software requirements and gateway or service options, making it possible to select the communications equipment alongside the heating plant.

Technology

The ISG Modbus documentation separates tables for WPMsystem, WPM 3/3i and other supported equipment families. It distinguishes input registers, writable holding registers, system states and energy data. It also explains the address convention, invalid-value marker and the need to compare a reading with the controller display. These details matter as much as knowing that a gateway supports Modbus TCP.

The ISG Connect manual and compatibility overview define the supported combinations. A local integration therefore identifies the heat pump, WPM controller, gateway and software together. One short site check can retain those identities, select a documented read-only value and compare it with the display. Optional service or energy-management functions remain separate from that data check. No write permission, universal register map or independent heat-meter accuracy is inferred from the presence of an ISG gateway.

Markets

The company overview presents building-services and indoor-comfort equipment, with operations in Germany and other markets. Its product history spans hot-water heating, heat pumps, ventilation and integrated heating and cooling. The WPL product information and installation manual address the equipment and engineering needed for an individual heating installation.

For projects that also need building-data access, the ISG compatibility overview provides a useful bridge between equipment selection and integration. It distinguishes controller generations and supported gateway/service options rather than describing all systems as one communications product. That is relevant when adding monitoring to an existing installation as well as specifying a new one. The company's Holzminden Energy Campus forms part of its training and communication provision around the equipment.

Company

STIEBEL ELTRON's official history names Theodor Stiebel and the 1924 start in Berlin. It records the move to Holzminden in 1944, where the headquarters remains. The company overview describes an internationally operating family-owned group and identifies Holzminden as a production, administration and training location.

The legal manufacturer is STIEBEL ELTRON GmbH & Co. KG, named in the ISG documentation with its Dr.-Stiebel-Straße 33 address in Holzminden. Its current offer connects the long-standing heating and hot-water business with local controls, network gateways and services. The Modbus documentation and compatibility tables provide detailed engineering information for that connected equipment, alongside the separate product installation manuals.

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References

  1. About STIEBEL ELTRON (opens in a new tab)
  2. History (opens in a new tab)
  3. WPL 25 AC (opens in a new tab)
  4. ISG Connect operation and installation manual (opens in a new tab) (PDF)
  5. ISG compatibility overview (opens in a new tab) (PDF)
  6. ISG Modbus TCP/IP software documentation, A 321798-47824-0146 (opens in a new tab) (PDF)
  7. WPL A, AC, AS and ACS operation and installation manual (opens in a new tab) (PDF)

This profile does not imply a commercial relationship with STIEBEL ELTRON and may contain inaccuracies.