Guldager

What Guldager does

Guldager A/S is a Danish water treatment and corrosion protection specialist founded in 1946 by Harald and Poul Guldager, sons of Alfred Guldager, whose 1923 invention of electrolytic cathodic protection for water pipes later became the global standard method for water-pipe corrosion protection. The company, headquartered in Allerød, Denmark, employs approximately 100 people (60 in Denmark) and is majority-owned by Danish private equity firm Capidea following a 2016 generational transition.

Guldager's product portfolio spans industrial water treatment plants, electrical deionization (EDI/ Geno-EDI-X), reverse osmosis systems (AVRO-flex 400 portable units through heavy-duty Geno-RK-X plants at 40-100 m³/hour), UV disinfection (violiQ:UV), water softening (UniSoft, softliQ:LB, Sycon hardness meter), Legionella control (chloriDOS iOX dosing, Hyprolyser iSEC electrolytic disinfection), desalination, filtration, glycol-based corrosion protection chemicals, and IoT/cloud temperature monitoring via UniLog. Sub-brands include Vision Watercare (reusable CTU filters and HoReCa monitoring, acquired January 2024) and ARO Energy Solutions (hot water tanks and district heating storage, acquired January 2024). The company also holds ISO 9001 and ISO 14001 certifications for its Swedish subsidiary and is a UN Global Compact signatory since 2020.

The business operates a full-service provider model generating revenue from one-time equipment sales (RO/EDI/UV plants, hot water tanks), recurring service contracts covering maintenance, inspection, and optimization, transactional chemical and additive sales (corrosion protection, glycol, Legionella control), and professional services (water analysis, risk assessment, consultancy). Guldager sells through direct enterprise field sales and a regional service organization across six European countries - Denmark, Sweden, Norway, Germany, Switzerland, and Belgium - serving more than 10,000 customers. Vertical focus spans properties, district heating, manufacturing, food and beverage, ports and shipping, HoReCa, pharmaceuticals and chemicals, swimming pools, energy, and offshore. Since 2020 the company has executed more than ten acquisitions to expand geographic reach, vertical coverage, and technical capabilities, including SBC-Inter, Drytech, POCOS, Stutz GmbH, SiWaTec AG, Hydro-X Scandinavia, Vision Watercare, ARO Energy Solutions, Grünbeck Belgium, and Envidan Process Water & Service.

Name

Guldager

Legal name

Guldager A/S

Website

https://guldager.com

Company type

Private

Founded year

1946

Operating status

Operating

Headcount range

51–100 employees

Short description

Guldager A/S is a Danish water treatment and corrosion protection company serving more than 10,000 customers across six European countries with equipment, chemicals, service contracts, and consultancy for industrial, property, district heating, and HoReCa applications.

Ownership category

akta.pro rank

Product category

Industrial Water Treatment Equipment

NAICS

Water, Sewage and Other Systems (2213), Environmental Consulting Services (541620), Water Supply and Irrigation Systems (22131)

SIC

Chemicals & Allied Products (2800), Specialty Cleaning, Polishing And Sanitation Preparations (2842), Miscellaneous Chemical Products (2890)

akta.pro primary industry

Water Treatment & Process Specialty Chemicals (IMAEABAN)

akta.pro secondary industries

Legionella Risk Assessment & Compliance Audits (BPABAJAA), Cooling Tower & Evaporative Condenser Water Treatment (BPABAJAC), Domestic Hot & Cold Water System Hygiene (Potable Water) (BPABAJAD), Disinfection & Remedial Works (Chlorination, Thermal, Shock Treatments) (BPABAJAF), Monitoring & Control (Dosing Systems, Remote Monitoring, Sensors) (BPABAJAK)

Keywords

• Water treatment systems
• Corrosion protection
• Industrial water purification
• Reverse osmosis solutions
• Water softening equipment

Headquarters

HQ city

Allerød

HQ country

Denmark

HQ region

Europe

Offices7 records

Markets served

GTM type

B2B

Offering type

Hardware or Manufacturing

Cost components

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

Revenue model

1. Water treatment equipment and plants: Sale of water treatment equipment including industrial water treatment systems, EDI/electrical deionization, reverse osmosis/RO plants, UV systems, softening systems, and filtration solutions
2. Service contracts and maintenance: Service agreements for water treatment plants, covering maintenance, inspection, and optimization of customer installations
3. Chemicals and additives: Sale of water treatment chemicals including products for corrosion protection, glycol, and Legionella control
4. Consulting and professional services: Water analysis, risk assessment, and advisory services related to water treatment and corrosion protection
5. Hot water tanks and storage (through ARO Energy): Production and delivery of hot water tanks, district heating units, buffer tanks, and buffer charging circuits for properties and industry

Go-to-market motion1 record

Distribution channels5 records

Marketing channels10 records

Core offering

Guldager designs, manufactures, sells, and services water treatment plants and corrosion protection equipment for industrial, commercial, residential, and HoReCa customers. Core offerings include reverse osmosis (RO) systems, EDI/electrical deionization, UV disinfection, water softening, desalination, electrolytic corrosion protection, and Legionella control systems, supplemented by chemicals/additives and recurring service contracts across Denmark, Sweden, Norway, Germany, Switzerland, and Belgium.

Product overview

Guldager A/S is a Danish water treatment company founded in 1946, offering comprehensive water treatment solutions and corrosion protection. The portfolio centers on core water treatment plant systems (industrial water treatment, EDI/electrical deionization, reverse osmosis/RO plants) complemented by specialized product modules for UV disinfection (violiQ:UV), water softening (UniSoft, softliQ:LB, Sycon), Legionella control (chloriDOS iOX, Hyprolyser iSEC), and desalination. The company operates through multiple sub-brands and acquired entities including Vision Watercare (now 'Vision Watercare by Guldager') offering CTU filters and IoT monitoring for HoReCa, and ARO Energy Solutions providing hot water tanks. Service offerings include tank cleaning, disinfection, risk assessment, pipe flushing, acid cleaning, water analysis, and cloud-based temperature monitoring via UniLog. The product range spans portable systems like AVRO-flex 400 to heavy-duty industrial units like Geno-RK-X (40-100 m³/hour), and addresses segments including properties, district heating, manufacturing, food/beverage, ports/shipping, pharma/chemical, swimming pools/spa, energy, and offshore.

Differentiator

Problem solved

Functional benefit

Brands

• Vision Watercare: Water treatment and softening solutions for hotel, restaurant and catering (HoReCa) sector, featuring reusable CTU filters and IoT-enabled monitoring systems.

Products and services

• AVRO-flex 400 Flexible and portable reverse osmosis system using patented AVRO pretreatment, enabling use without water softening for industrial, commercial, and HoReCa customers needing ultra-pure water on demand.
• Geno-RK-X Heavy-duty industrial reverse osmosis system delivering 40 to 100 m³/hour for large-scale water desalination and process water needs in manufacturing industries.
• Geno-EDI-X Electrical deionization (EDI) system that performs final demineralization as a polishing step after a GENO-OSMO reverse osmosis system, producing ultra-pure water for industrial and commercial customers.
• violiQ:UV UV disinfection system designed for cold drinking water disinfection, installed downstream of water treatment plants to provide microbiologically safe water.
• Hyprolyser iSEC On-site electrolytic disinfection system that produces hypochlorite from salt, water, and electricity for continuous Legionella prevention in hot water installations in properties, healthcare, and industrial facilities.
• chloriDOS iOX Dosing system that injects measured amounts of chlorine dioxide or similar biocides to combat Legionella in water-borne systems for property, healthcare, and industrial customers.
• softliQ:LB Water softening system engineered for treating large volumes of water with low pressure loss, suitable for properties, commercial buildings, and industrial customers.
• Sycon Industrial-grade hardness meter that continuously monitors water hardness to ensure soft water delivery in industrial and commercial softening installations.
• Alpha-B Dynamic string control valve designed for hot domestic water flow regulation in property and district heating applications, supporting corrosion protection and Legionella control strategies.
• UniLog Wireless temperature monitoring system that transmits water heating system temperatures to a Guldager-monitored cloud platform, supporting Legionella compliance and remote service for property and district heating customers.
• Water Filters for Legionella Emergency Emergency point-of-use filters attachable to shower hoses, mixing faucets, or water taps during Legionella incidents, allowing continued water use while the system is disinfected.
• CTU Filters (Vision Watercare) Reusable Calcium Treatment Unit (CTU) filters designed for large coffee machines, vending machines, and professional kitchens in the HoReCa sector - more economical and environmentally friendly than disposable alternatives.
• Potable Water Makers Systems for producing potable drinking water from various source waters including seawater and brackish water for industrial, commercial, and offshore customers.
• Glycol Products (DowCal) DowCal glycol solutions used for corrosion protection and freeze protection in heating, cooling, and district heating systems, sold as a consumable to property and industrial customers.
• Water Treatment Chemicals Chemical consumables for industrial water treatment including district heating and power plant applications, supplied on transaction basis alongside Guldager's service contracts.
• Water Treatment Service Contracts Recurring field service contracts covering maintenance, inspection, optimization, tank cleaning/disinfection, risk assessments, pipe flushing, acid cleaning, water analysis, and remote IoT monitoring for properties, industry, and HoReCa customers.
• Vision Watercare (HoReCa sub-brand) HoReCa-focused water treatment and softening sub-brand offering CTU filters, IoT-connected monitoring, and water treatment solutions for hotels, restaurants, and catering operators, integrated into Guldager in 2024 via the Servicebilen ApS acquisition.
• Industrial Water Treatment Plants Custom-engineered complete water treatment plants and systems for industrial, commercial, and residential applications - Guldager's core product line integrating RO, EDI, UV, softening, and filtration.

Quantifiable outcome

• 2020 showed best operating income and highest net result in 5 years despite COVID-19
• +1 more outcomes

Named customers7 records

Segments10 records

Ideal customer profiles5 records

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature9 records

Partnerships

Twelve partnerships are on record, tiered core and minor.

• Envidan Group (Sweden)coreStrategic or Co-development Partner · 1 May 2024Guldager acquired the Process Water & Service business area from Envidan Group in Sweden. 9 employees and premises in Solna taken over. Strengthens presence in Swedish industrial water treatment market.
• ARO Energy Solutions A/ScoreStrategic or Co-development Partner · 18 January 2024Acquisition of ARO Energy Solutions provides foothold in production and delivery of hot water tanks for properties and industry. Company continues under its own name with Guldager as sole shareholder. All contracts and service agreements continue.
• Servicebilen ApS / Vision WatercarecoreStrategic or Co-development Partner · 1 January 2024Acquisition of Vision Watercare brings CTU filter technology (reusable filters for coffee and vending machines) and IoT-connected monitoring system for HoReCa sector. Founder Svend Bødtker Nielsen became Head of Guldager's HoReCa department (Vision Watercare by Guldager).
• Grünbeck Wasseraufbereitung GmbH (Belgium)coreStrategic or Co-development Partner · 1 January 2024Guldager N.V. acquired Grünbeck's Belgian subsidiary Grünbeck BVBA, which focused on water softening for private households. Combined forces enable delivery of wide range of products and services to both industry and residential sector.
• Hydro-X Scandinavia (Sweden and Norway)coreStrategic or Co-development Partner · 1 November 2022Guldager acquired all Hydro-X Scandinavian sales and service activities including shares in Hydro-X Sweden and Hydro-X Norway, bringing nearly 1,000 new customers and strengthening full-service provider concept in Scandinavia.
• SiWaTec AG (Switzerland)coreStrategic or Co-development Partner · 20 December 2021Acquisition of 100% Swiss company founded in 2001 by Ignaz Schneider. Specializes in renovation, repair, and maintenance of public and private swimming pools, baths, and fountains.
• Hydro-XcoreStrategic or Co-development Partner · 13 October 2021Strategic partnership between Guldager A/S and North Jutland company Hydro-X, which has delivered chemical products for water treatment in industrial and power plant sectors for many years. Purpose was to exploit synergies with focus on joint business opportunities in Europe through utilization of know-how, products, and services. Hydro-X had a large partner network with extensive experience in water and cooling treatment and multiple ISO certifications.
• Stutz GmbH (Germany)coreStrategic or Co-development Partner · 1 September 2021Acquisition of German company founded in 2007 by Axel Stutz. Focus on repair and maintenance of public swimming pools, waterworks, and industrial water treatment.
• Thomas Bauer Wassertechnischer Vertrieb (Germany)coreStrategic or Co-development Partner · 1 May 2021Acquisition by Guldager GmbH of company established by Thomas Bauer in 1997. Focus on repair and maintenance of public swimming pools including chlorine gas systems service and measurement/control technology.
• POCOS (Polar Corrosion Services)coreStrategic or Co-development Partner · 1 August 2020Acquisition of Danish company founded in 2011 by engineer Jan Almqvist. Specializes in corrosion protection for Danish ports and steel structures in soil.
• SBC-Inter and Drytech (Denmark)coreStrategic or Co-development Partner · 1 July 2020Acquisition of Danish companies SBC-Inter (founded 1975, corrosion protection, cleaning of cooling systems, acid cleaning) and Drytech (founded 2012, basement drying systems using electroosmosis).
• FlowplanminorGTM or Marketing PartnerCollaboration partner featured in video content for filter change demonstrations. Flowplan appears in marketing content for Guldager products.

Scale indicators5 records

Recent moves8 records

Expansion highlights6 records

Direct peers

• BWT (Best Water Technology): Austrian-headquartered European specialist in water treatment technologies including softening, filtration, Legionella control, and dosing systems. Closely comparable to Guldager in product scope, customer verticals (properties, HoReCa, industrial), and European mid-market positioning.
• Grünbeck Wasseraufbereitung: German family-owned water treatment specialist offering softening, filtration, and Legionella protection products and services. Directly comparable to Guldager — note that Guldager acquired Grünbeck's Belgian subsidiary (Grünbeck BVBA) in 2024, indicating head-to-head competition in adjacent markets.
• Lenntech: Dutch water treatment solutions provider specializing in filtration, softening, reverse osmosis, and disinfection systems for industrial and commercial clients across Europe and emerging markets. Comparable to Guldager in European mid-market positioning and product mix.
• EnviroChemie: German-based specialist in industrial water treatment, water recycling, and process water solutions for manufacturing, pharma, and chemical sectors. Directly comparable to Guldager's industrial water treatment and chemicals offering, particularly across the German-speaking market where Guldager now operates via Stutz GmbH.

Broad incumbents

• Culligan International: Global water treatment company offering residential, commercial, and industrial water filtration, softening, and treatment solutions with both direct and dealer-led distribution. Comparable in product breadth and recurring service model, but at much larger scale and global footprint than Guldager.
• Pentair: US-listed global water solutions company offering residential, commercial, and industrial water treatment equipment and services. Overlaps with Guldager in filtration, softening, and industrial water treatment but operates at far larger scale with global channel reach.
• Veolia Water Technologies: Global leader in water and wastewater treatment services and technologies, serving industrial and municipal clients worldwide. Comparable to Guldager's industrial process water and treatment chemicals offerings, but at vastly larger scale and as part of a broader environmental services portfolio.
• Watts Water Technologies: US-listed manufacturer of water treatment, conservation, and flow control products for residential, commercial, and industrial applications. Comparable in plumbing and water quality product portfolios, though distributed through wholesale channels rather than direct service like Guldager.
• Xylem: Global water technology company providing pumps, treatment, and metering solutions for utility, industrial, residential, and commercial applications. Overlaps with Guldager in industrial water treatment, metering, and disinfection but at much larger scale and broader product portfolio.

Others

• Hydro-X (Hydro-X International): North Jutland-based provider of water treatment chemicals and services for industrial and power plant sectors. Hydro-X Scandinavia was acquired by Guldager in 2022, and Hydro-X International remains a co-owner — making it a former direct competitor and now both a strategic partner and historical comparable for Guldager's industrial chemicals business.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat5 records

Key risks6 records

Key highlights7 records

Customer concentration

• Xfacebook.com/Guldagerdanmark
• YouTubeyoutube.com/channel/UCM6ie17qlegwYHAj7eKraeQ
• Facebookfacebook.com/Guldagerdanmark
• LinkedInlinkedin.com/company/guldager-a-s
• Instagraminstagram.com/guldagerdk

Compliance5 records

Revenue estimate

Valuation estimate

Number of profiles

Profiles5 records

Subsidiaries12 records

Funding overview

Funding rounds1 record

Investors1 record

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 Guldager