Heating water as a heat transfer medium is one of the most important components of a heating system. If drinking water is simply filled into the heating system without appropriate treatment, this carelessness will pay off sooner or later. Over 90% of malfunctions and damage in heating systems result from incorrect heating water. Whether jammed valves, stuck pumps or muddy underfloor heating circuits. In most cases, the symptoms are due to untreated heating water. With coracon® heating protection products you safely prevent rust, limescale and other deposits.

The following processes also occur with modern heating systems:

  • Corrosion
  • Emergence of leaks
  • Formation of scale and sludge

This can repeatedly cause malfunctions of pumps, valves and radiators, increased heating costs, increased costs for process and waste water and, last but not least, premature wear of the heating system.

During normal operation, these problems are usually not observable in the first years of operation. The problems usually do not appear until several years later. Especially after longer summer breaks at the beginning of the heating season. Therefore, it is essential, if possible, from the outset, to take measures that lead to efficient and trouble-free operation of the water circuits of heating systems in order to maximize the operational reliability and functionality of the circuit throughout the life of the equipment.

Heating water is basically corrosive to ferrous materials. But it also corrodes non-ferrous metals such as copper and brass. Attempts to displace oxygen from the heating water during the summer usually fail because the water in the heating system is cold. Therefore, in addition to the selection of a suitable construction material, adequate water care in heating systems is also important. This can adequately reduce the requirements for a range of quality materials. It is necessary to add corrosion inhibitors to fresh water. These create a protective layer on the surface of the material and thus reduce the corrosive effects of water. This procedure is independent of whether the water is flowing or at rest.

In addition, it must be borne in mind that the fresh water contains dissolved salts which form, in particular, limestone deposits, when adding unsoftened or only partially softened water. If necessary, fresh water must be softened before being added to the circulation.

If there are already corrosion particles in the system, it is recommended to use CORACON water heating filters. Aqua-Concept has been using these hot water filters with success for many years, for example in motor cooling circuits, where they have proven themselves very well. Their robust construction guarantees a very long service life and minimal maintenance requirements. The use of these filters results in clean, unhardened heating water, thus reducing the problems associated with erosion and clogging of the system. The size of the CORACON water heating filters depends on the volume of the heating water circuit. There are filters for systems from 20 to 40,000 liters.


The corrosive effects of water are closely related to the substances contained in water, which can be demonstrated by a suitable laboratory test. By using the sample for corrosion testing, the effects of corrosion are visible within about 14 days.

Comparative measurements after the addition of a suitable anti-corrosion agent will usually show significant differences. By adding a tested anti-corrosion agent from the CORACON product line, a significant improvement is usually achieved, when a factor of 40 is achieved, which means that the anti-corrosion protection is effective from approx. 97-98%.

This measurement can of course also be performed in a heating system. The so-called corrosion coupon is attached to the selected zone in the holder and an evaluation is performed in about 3 to 6 months.

Your benefits of consistent water care in steam and heating systems are:

  • Corrosion protection working with a protective layer on a metal surface and displacing oxygen
  • Prevention of calcium deposits by adding effective hardness stabilizers
  • Slow degradation of existing calcium coatings is possible
  • Significant fuel and energy savings by preventing the formation of calcium deposits and corrosion products
  • Lower costs for replacement of technological parts and lower need for cleaning
  • Compliance with relevant standards
  • Corrosion protection and filtration system from one source
  • Reduced sludge volumes in heating systems