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Solar Thermal Products - Solar KEYMARK

Solar laboratory

Solar thermal products make an important contribution to the conservation of fossil energy. The sun provides enough heat to cover 50 to 70 % of the average annual need of hot water of a 4-person-household and only a few square meters of collector surface are needed. Leading to a reduced operation of the boiler this saves not only our environment but also the purse.

The core of every thermal solar system is the solar collector transforming the solar rays directly into available energy. A broad range of technically matured flat-plate and vacuum tube collectors comes into operation. At the same time, the market for complete solar systems becomes more and more unmanageable. For planner, installer and consumers it is increasingly difficult to decide on the right product, especially as these products are hardly distinguishable. Therefore the decision is mostly taken in favour of the apparently lowest-priced product.

Since a product quality has significant influence on its life, the right purchase decision is worth hard cash for the customers.

You will find more information also at ESTIF – European Solar Thermal Industry Federation.


Confidence is good - KEYMARK and DIN-Geprüft are better

Also the overview on certification and quality marks is also becoming more and more difficult because they strongly differ also in the testing and surveillance criteria. To counteract the torrent of marks, the European Standards Organizations CEN and CENELEC established the European quality mark "KEYMARK", giving the manufacturer the opportunity to convince users and consumers of the quality of his products. This meaningful certification gives the manufacturer a market advantage against his competitors.

Testing and certification foundations for Solar KEYMARK

As already successfully practised with the certification of thermal insulation products for buildings, a European harmonized certification procedure has also been established for solar thermal products (solar collectors and factory made systems).

It applies to the following products:

  • Solar collectors (flat-plate collectors, tube collectors, concentrated collectors, PVT collectors, solar air collectors)
  • Custom built systems
  • Solar water heater stores (inclusive solar combistores)
  • Control equipment for thermal solar systems

This certification scheme have been drawn up with the participation of manufacturers, testing laboratories, certification bodies as well as the European federation of the solar industry ESTIF (European Solar Thermal Industry).

It specifies that manufacturers have their products been tested and surveyed according to the common European quality criteria by neutral, independent and competent bodies. That improves the confidence of users and consumers – throughout Europe.

The KEYMARK is granted in combination with the certification mark "DIN-Geprüft" on the basis of the European certification scheme for solar thermal products that is based of these two European product standards:

  • DIN EN ISO 9806 "Solar energy - solar thermal collectors - Test methods"
  • DIN EN 12975-1"Thermal solar systems and components - Collectors - Part 1: General requirements"
  • DIN EN 12976-1 "Thermal solar systems and components - Factory made systems - Part 1: General requirements"
  • DIN EN 12976-2 "Thermal solar systems and components - Factory made systems - Part 2: Test methods"
  • DIN EN 12977-1 "Thermal solar systems and components - Custom built systems - Part 1: General requirements for solar water heaters and combisystems"
  • DIN EN 12977-2" Thermal solar systems and components - Custom built systems - Part 2: Test methods for solar water heaters and combisystems"
  • DIN EN 12977-3"Thermal solar systems and components - Custom built systems - Part 3: Performance test methods for solar water heater stores"
  • DIN EN 12977-4"Thermal solar systems and components - Custom built systems - Part 4: Performance test methods for solar combistores"
  • DIN EN 12977-5"Thermal solar systems and components - Custom built systems - Part 5: Performance test methods for control equipment"

These specify the requirements and testing procedures for solar collectors, solar thermal systems and solar water heater stores concerning usability, safety and reliability as well as for the determination of the thermal efficiency of a solar collector or a solar system.

Quality criteria

The following quality criteria are subject to the testing of solar collectors:

  • Internal pressure resistance
  • Mechanical load
  • High temperature resistance
  • Internal and external thermal shock resistance
  • Exposure
  • Rain proof
  • Impact resistance
  • Thermal performance

For thermal solar systems the following characteristics are addtitionally tested:

  • Suitability for drinking water
  • Freeze resistance overtemperature protection
  • Reverse flow protection
  • Pressure resistance
  • Safety equipment

Furthermore the manufacturer has to operate, in both cases, a product related factory production control taking into account the elements of the EN ISO 9000 series.

Testing and assessment

Only those solar thermal products are certified with the KEYMARK in combination with "DIN-Geprüft" which were successfully tested by a testing laboratory approved by the CEN Certification Board and DIN CERTCO, neutrally assessed and thus proofed the compliance with the relevant standards.

After a positive result of the assessment DIN CERTCO issues a certificate that is valid for 5 years. It can be renewed for further 5 years if applied for, provided that the surveillance (annual inspection of the factory and physical inspection of the product at least every 2 years) shows that the preconditions are fulfilled.

For further information about the Solar KEYMARK please visit


FAQ - Frequently Asked Questions

  • Solar KEYMARK also available for air collectors, PVT, solar water heater stores, solar combistores and control equipment
    • Air Collectors

      Due to the new internationally harmonized testing procedures in DIN EN ISO 9806:2014-03, covered and uncovered air collectors can now be certified according to the Solar KEYMARK Scheme Rules, which are the basis for government incentives in many European countries.

      PVT Collectors

      Since 2013 PVT collectors can be tested and certified. Much work has been done with regard to this subject within the Solar KEYMARK Network. According to the current version of the „Specific CEN Keymark Scheme Rules for Solar Thermal Products“, the following tests have to be performed:

      • DIN EN 61730-1; VDE 0126-30-1:2007-10:2007-10 for Photovoltaic (PV) module safety qualification - Part 1: Requirements for construction (IEC 61730-1:2004, modified)
      • DIN EN 61215; VDE 0126-31:2006-02:2006-02 for Crystalline silicon terrestrial photovoltaic (PV) modules – design qualification and type approval (IEC 61215:2005)

      on the PV module being part of the PVT collector by a DIN EN ISO/IEC 17025 accredited testing laboratory. It is mandatory to supply a valid certificate for the PV module. With a declaration made by the certification body that issued the PV certificate the conformity of the PVT collector can be confirmed. No changes apply to the testing procedure according to DIN EN 12975-1:2011-01.

      Solar water heater stores, solar combistores and control equipment.

      Following the publishing of the standard series DIN EN 12977 in May 2012 new certifications have become available. Manufacturers, traders and distributors of solar water heater stores (according to DIN EN 12977-3:2012-06), solar combistores (according to DIN EN 12977-4:2012-06) and control equipment (according to DIN EN 12977-5:2012-06) can now apply for Solar KEYMARK certification.

      The procedure and requirements for certification are described in the current version of the “Specific CEN Keymark Scheme Rules for Solar Thermal Products”.

  • Testing and certification of products according to DIN EN ISO 9806:2014-03.
    • In March 2014 the new ISO standard has been published and entered into force. The transition rules are under development and will be transmitted to you upon completion. More details regarding transition rules are to follow.

  • Testing for second renewal of certificates
    • To grant a quick reaction to changes of the standard or product changes, the CEN Certification Board (CCB) in Brussels has revised the internal regulations for the solar KEYMARK and limited the validity of certificates to a maximum of 5 years.

      Additionally the overall validity has been set to 10 years. This means, for the second renewal of the certificate a type test will be necessary. Following the positive outcome of this type test and an application for renewal the certificate can be issued.

      The first renewal of the certificate will - as previously - be issued on the basis of the positive outcome of the duly carried out Physical Inspection (PI) and Factory Inspection (FI).

  • Annual licence fees for Solar KEYMARK since 2014.
    • Due to the difficult financial situation of the solar thermal industry sector the Solar Thermal Industry Federation (ESTIF) has succeeded to reduce the costs.

      By 2014 only 50 € for the first certificate and for every additional certificate 230 € are charged. These fees are used for the maintenance and continuous development of the Solar KEYMARK scheme rules and its implementation by the Solar KEYMARK Network.

      The price reduction leads to relatively lower licence fees especially for certificate holders with a number of certificates. The annual licence fee from DIN CERTCO will be adjusted accordingly.

      Furthermore a request for reduction of licence fees has been sent to CEN Certification Board (CCB).

  • Blacklist - Misuse of Solar KEYMARK
    • For the DIN CERTCO Blacklist with the companies using our legally protected quality marks please use click here. .

  • How can traders/distributors benefit from Solar KEYMARK certification?
    • According to the accreditation requirements of DIN EN ISO/IEC 17065 every certification body is obliged to prevent the misuse of its certificates and quality marks.

      The right to use the mark is in principle only given to the certificate holder, after positive outcome of the certification procedure.

      Under some circumstances also traders/distributors of products are allowed to use the Solar KEYMARK. The following conditions apply:

      • You apply for a solar KEYMARK-certificate (OEM/OBL-certificate) with a reduced testing and inspection expenditure and receive a positive assessment of all certification relevant documents leading to the right to use the mark including the respective registration number.
      • You refer to the manufacturer (certificate holder) of the product and state the respective registration number. The product name/brand has to be identical with the manufacturers (certificate holder).

      Please note: It has to be ensured, that it is unmistakable that the trader/distributor is not the certificate holder and does not possess the right to use the mark.

  • Solar KEYMARK for traders/distributors of certified products (OEM certificates)
    • Here, we describe the necessary steps to the solar KEYMARK certification for OEM customers who want to place already certified products under its own brand name on the market. For OEM customers it is quite easy to be granted the Solar KEYMARK. The main advantage is that they do not need to pass a complete new product test and the annual inspections and thus save these costs.

      For this, the customer has to contact the authorized certification body which also has issued the certificate of the already certified product of the manufacturer.

      For the certification procedure, the following documents have to be send to DIN CERTCO:

      • For every new product, we need an original signed version of the application form from the OEM customer (to be the certificate holder). Please make sure that the registration No. of the valid Solar KEYMARK certification is mentioned.
      • From the manufacturer (certificate holder) we need a confirmation in writing that the OEM customer is allowed to use the test report and inspection report for the certified product and that the product of the OEM customer is from the technical point of view identical to the type-tested one.
      • The testing laboratory shall supply us with a new version of the test report with the contact details of the OEM customer and a new test report No. This test report could be sent to us also as an pdf-file directly from the testing laboratory.
      • The type plate and installation manual or assembly instruction of OEM customers must be submitted to the testing laboratory for testing.
      • Furthermore, we need from the testing laboratory the relevant Solar KEYMARK data sheet as PDF and an excel-file. The required registration No. will be sent to the testing laboratory after we have received the application form.

      Please contact for these documents directly the appropriate testing laboratory who carried out the initial type test.

      With the manufacturer (certificate holders) must be agreed whether the OEM certificate shall be applied and issued for all or only a part of sub-types. This affects the fees payable.

      After receiving the application form, we will send an order confirmation to the OEM customer with a list of the missing documents. With the complete set of application documents we will do the conformity assessment and - if the result is positive - issue a new Solar KEYMARK certificate with a unique registration No.

      Furthermore, the OEM customer will be issued on our website on the list of certificate holders for the Solar KEYMARK. Thus it would be fine if we receive the

    • company logo
    • as a jpg or gif file in time.

      Of course, we will provide the OEM customer also with the file of the KEYMARK so that he can use it for his website, for the brochures and for the certified product itself. Please make sure that the KEYMARK has always to be used in combination with the registration No. to avoid actions against a misuse of the mark .

  • Frequency of Factory Inspections and Physical Inspections for manufacturers and OEM-customers
    • According to the accreditation requirements of DIN EN ISO/IEC 17065, we, as a certification body, are obliged to inform all certificate holders continually of deadlines for renewal and surveillance measures regarding their certificates and to follow up on the proper implementation thereof. The responsibility for certification relevant questions however remains with the certificate holder.

      According to the current version of the Solar KEYMARK Scheme Rules, the following surveillance measures for certified products apply after initial certification:

      • Physical Inspection (checking of the certified product(s)) every two years
      • Factory Inspection (checking of the quality management procedures) every year

      For companies that are certified according to DIN EN ISO 9001:2008-12, the FI can also be performed only once every two years. The FI will only be performed at the manufacturer.

      All OEM/OBL-certificates however must be mentioned in the FI report and remain part of the assessment procedure of DIN CERTCO. All certificate holders receive a letter with the results from the assessment after each assessment. This is charged according to our current schedule of fees.

  • Admit a solar collector to the BAFA-list of eligible collectors
    • The following documents/proofs needs the Federal Office of

    • Economics and Export Control (BAFA)
    • to admit a solar collector to the BAFA-list of eligible collectors:

      • Certificate Solar KEYMARK (provided by an accredited and empowered certification body
      • www.solarkeymark.org
      • )
      • Test report according to EN 12975 (prepared by an accredited testing laboratory). Change of manufacturer’s test report for OEM-collectors
      • Proof of annual collector gain (annual energy gain) of at least 525 kWh/m² for "location Würzburg" (prepared by an accredited testing laboratory)
      • Manufacturer’s declaration of compliance with criterias of eco-label RAL UZ 73 (Blue Angel)

      For further information about the Solar KEYMARK, please

    • click here
    • .

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