aqua calor

What aqua calor does

aqua calor GmbH is a German private limited company (GmbH) headquartered at Prager Str. 17, 04103 Leipzig, specializing in consumption-based heating cost billing (Heizkostenabrechnung) and adjacent regulatory compliance services for residential rental properties. The company was formed through the 2024 merger of aqua calor and meine Wärme GmbH, with the aqua calor brand retained as the larger and more market-recognized entity; Gunter Schwalm and Steffen Foede continue as managing directors alongside newly appointed Mario Dietz. Its core product portfolio comprises four device categories — electronic heat cost allocators (exclusively 2-sensor technology), water meters, ultrasonic heat meters, and smoke detectors — all sourced from established suppliers (allmess GmbH, Qundis, Ei electronics) and upgradeable for radio-enabled remote reading. These devices feed the company's primary service: legally compliant heating, hot water, and ancillary cost accounting for landlords and property managers under the German Heating Cost Ordinance (HeizkostenV), with supporting offerings in energy certificates, drinking water/Legionella testing, meter inspection, and the UVI (Unterjährige Verbrauchsinformation) monthly consumption information portal.

The business operates a recurring revenue model anchored by meter rental contracts bundled into annual billing, supplemented by per-unit inspection fees (regulated under MessEGebV, most recently updated December 2025) and project-based professional services such as drinking water testing. Distribution is direct-to-customer via the aqua-calor.de website (built on Worldsoft CMS with Worldsoft Business Suite CRM), phone and email customer service, and field service teams covering Leipzig and Chemnitz; large property managers submit billing data through the HKKOSTI portal while tenants access consumption information via the UVI portal. Customers are primarily property owners, landlords, property management companies (Wohnungsverwaltungen), and homeowner associations (WEG) — a horizontal mid-market and SMB segment with no disclosed anchor accounts. Geographic focus is Saxony with broader German reach through the website, and the company holds no disclosed external funding, operating as a privately held founder/family-owned entity with no parent company or institutional investors identified.

Name

aqua calor

Legal name

aqua calor GmbH

Website

https://aqua-calor.de

Company type

Private

Founded year

2005

Operating status

Operating

Headcount range

11–50 employees

Short description

aqua calor GmbH is a Leipzig-based German service provider specializing in consumption-based heating cost billing, meter rental, and regulatory compliance services — including Legionella testing and smoke detectors — for landlords and property managers, primarily in Saxony.

Ownership category

akta.pro rank

Product category

Heating Cost Billing & Utility Metering Services

SIC

Totalizing Fluid Meters & Counting Devices (3824)

akta.pro primary industry

Submetering & Multi-Unit Property Billing (MUDs, submeters, RUBS, landlord/tenant billing) (EUANAIAK)

akta.pro secondary industry

Cooling Tower & Evaporative Condenser Water Treatment (BPABAJAC)

Keywords

• Heating cost billing
• Consumption-based metering
• Energy certificate services
• Drinking water testing
• Smoke detector services

Headquarters

HQ city

Leipzig

HQ country

Germany

HQ region

Europe

Offices1 record

Markets served

GTM type

B2B

Offering type

Services

Cost components

Personnel, Operations, Supply Chain, Technology or R&D, Marketing or Sales, Infrastructure

Revenue model

1. Heizkostenabrechnung (Heating Cost Billing): Creation of consumption-based heating and hot water cost accounting for rented units, including cold water accounting and ancillary cost accounting. This is the core service of the company.
2. Messgerätevermietung (Meter Rental): Rental of water meters, heat meters, heat cost allocators, and smoke detectors under various contract forms. Devices are regularly replaced per legal requirements (calibration/certification cycles). Rental costs are included in the billing.
3. Zählerüberprüfung (Meter Inspection): Verification testing of water meters and heat meters at state-recognized testing facilities, including reference testing of heat cost allocators. Fees are charged per device tested.
4. Trinkwasserbeprobung (Drinking Water Testing): Legionella testing services for large hot water systems, including plant documentation, sampling coordination, laboratory analytics, and results reporting.
5. Rauchwarnmelderservice (Smoke Detector Service): Rental, installation, and maintenance of smoke detectors including remote inspection services (Bauweise C) for multi-unit residential buildings.

Pricing tiers

Go-to-market motion2 records

Distribution channels4 records

Marketing channels5 records

Core offering

aqua calor GmbH delivers consumption-based heating cost billing (Heizkostenabrechnung) and ancillary cost accounting for German rental residential properties, bundled with rental of calibrated metering devices (heat cost allocators, water meters, heat meters, smoke detectors). The portfolio also includes smoke detector installation/maintenance, Legionella drinking water testing for large hot water systems, consumption-based energy certificates, and monthly interim consumption information (UVI) delivered through an online tenant portal.

Product overview

aqua calor GmbH is a specialized billing and measurement services company for rental properties in Germany. The product portfolio centers on four core measurement devices—heat cost allocators, water meters, heat meters, and smoke detectors—all available with radio/remote reading capabilities. These devices form the foundation for their billing services, including heating cost billing, water cost accounting, and ancillary cost calculations. The company also offers supporting services including meter device rental/maintenance, energy certificates, drinking water testing for legionella, and online tenant portals for consumption information. The architecture is device-centric: customers rent or purchase measurement devices, which generate consumption data that feeds into aqua calor's billing platform, with additional services built around regulatory compliance (energy certificates, water testing) and tenant communication (interim consumption information).

Differentiator

Problem solved

Functional benefit

Products and services

• Abrechnung (Heating Cost Billing Services) Consumption-based heating cost billing (Heizkostenabrechnung), hot water billing, optional cold water billing, and complete ancillary cost accounting (Nebenkostenabrechnung) for landlords and property managers, compliant with the German Heating Cost Ordinance. Service spans from organizing meter readings to producing finalized individual tenant bills.
• Messgeräteservice (Meter Device Rental & Maintenance) Rental of water meters, heat meters, heat cost allocators, and smoke detectors under contractual terms, including scheduled replacement per Measurement and Calibration Law requirements. Rental costs are bundled into the annual billing. Covers installation, calibration replacement, and device failure coverage.
• Energieausweis (Consumption-Based Energy Certificates) Consumption-based energy certificates (verbrauchsbasierter Energieausweis) for buildings, required for sale, rental, and leasing. Built on actual energy consumption data from heating cost bills aqua calor already produces for the property.
• Trinkwasseruntersuchung (Legionella Drinking Water Testing) Legionella testing services for large hot water systems as required by the German Drinking Water Ordinance (TrinkwV). Includes plant documentation, sampling coordination, certified laboratory analysis, and reporting of results to property owners.
• Rauchwarnmelder (Smoke Detector Rental, Installation & Maintenance) Rental, installation, and maintenance of smoke detectors for multi-unit residential buildings per Saxony building regulations, including remote inspection models (Bauweise C) such as Ei6500 and iSD. Devices comply with DIN EN 14604 and Q-Label (VdS 3131).
• Heizkostenverteiler (Electronic Heat Cost Allocators) Electronic heat cost allocators that measure and distribute heating costs based on individual consumption. aqua calor exclusively uses 2-sensor technology for superior accuracy. Available in radio-enabled variants for remote reading.
• Wasserzähler (Water Meters) Water meters for residential (Q3 up to 4.0 m³/h) and commercial applications (up to Q3 16 m³/h), in surface-mounted and subsurface-mounted variants. All models are upgradeable for remote reading via wired or wireless modules.
• Wärmezähler (Ultrasonic Heat Meters) Calibrated ultrasonic heat meters (UltraMaXX and UltraLite) for precise energy consumption measurement, with optional radio module upgrades. Also available in cooling and combination versions for climate-controlled buildings.
• Zählerüberprüfung (Meter Verification Testing) Verification testing (Befundprüfung) of water meters and heat meters at the state-recognized testing facility at Allmess GmbH, including reference testing of heat cost allocators. Fees per MessEGebV (effective December 2025).
• Unterjährige Verbrauchsinformation - UVI (Monthly Consumption Information Service) Monthly interim consumption information service providing tenants regular updates on heating and hot water usage, based on European Energy Efficiency Directive requirements. Accessed via the UVI online portal at https://aqua-calor.de/uvi.

Quantifiable outcome

• Each degree Celsius reduction in room temperature saves approximately 6% in heating costs
• +2 more outcomes

Segments3 records

Ideal customer profiles2 records

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature2 records

Partnerships

Four partnerships are on record, tiered core.

• meine Wärme GmbHcoreStrategic or Co-development Partner · 1 January 2024meine Wärme GmbH merged into aqua calor GmbH in 2024. The merger was driven by a pending generational change in management, increasingly complex legal requirements making dual-brand operations economically difficult, and the fact that aqua calor was the larger and better-known brand. All contracts from meine Wärme GmbH continue under aqua calor GmbH. Gunter Schwalm, formerly sole managing director of meine Wärme GmbH, joined the management of aqua calor alongside Steffen Foede.
• allmess GmbHcoreTechnology or Integrationallmess GmbH is the primary supplier of water meters, heat meters, electronic heat cost allocators, smoke detectors, and radio reading systems used by aqua calor. aqua calor relies on allmess products for its core metering equipment across all product categories. The partnership is described as a long-standing relationship with 'beste Erfahrungen' (best experience).
• QundiscoreTechnology or IntegrationQundis supplies electronic heat cost allocators and radio reading systems to aqua calor. The company is a key technology partner alongside allmess for the core metering technology used in aqua calor's billing services.
• Ei electronics (Ei Electronics)coreTechnology or IntegrationEi electronics supplies smoke detectors to aqua calor, including models Ei650i (manual maintenance), Ei650FA (partial remote inspection), Ei6500 and iSD (remote inspection / Bauweise C). Quality focus for smoke detectors includes VdS certification, Q-label per VdS 3131/vfdb-Richtlinie 14-01, and DIN EN 14604 compliance.

Scale indicators1 record

Recent moves6 records

Expansion highlights5 records

Direct peers

• ISTA SE: Germany's largest submetering and heating cost billing service provider, offering the same end-to-end portfolio of metering devices, billing, and consumption-based services to landlords and property managers as aqua calor.
• Techem GmbH: Major German submetering and energy services company providing heating cost billing, water/heat meters, smoke detector services, and energy certificates — direct line-for-line competitor to aqua calor's offering.
• Immocon GmbH: Smaller German submetering and heating cost billing service provider targeting landlords and property managers — competes with aqua calor in the same mid-market German regional segment.
• Minol Messtechnik W. Lehmann GmbH & Co. KG: German metering and billing service provider (Minol/Zenner group) competing in heating cost allocation, water metering, smoke detector service, and consumption-based billing for residential properties.
• BRUNATA-METRONA GmbH: Long-established German submetering and heat cost allocation company offering metering hardware, billing services, and related property compliance services across Germany — direct competitor to aqua calor.
• KALORIMETA GmbH: German heat cost allocation and submetering specialist serving landlords with metering, billing, and ancillary services — directly comparable in product scope and target customer to aqua calor.

Others

• co2online GmbH: Non-profit advisory service for energy-efficient modernization in Germany — not a billing competitor, but a complementary ecosystem player whose CO2 cost-sharing content overlaps with aqua calor's regulatory compliance positioning.
• Diehl Metering GmbH: Manufacturer of water and heat meters (Hydrometer, Diehl brand) supplying the German submetering market — adjacent ecosystem participant rather than direct competitor, but supplies the type of metering hardware aqua calor rents.

Market position

Strengths4 records

Weaknesses5 records

Competitive moat4 records

Key risks5 records

Key highlights6 records

Customer concentration

• LinkedInlinkedin.com/company/aqua-calor-gmbh

Revenue estimate

Valuation estimate

Number of profiles

Profiles4 records

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about aqua calor