Are you using the best solution to fill and maintain your heating water?

After reading many social media posts and a great chat with David Whitfield of Elysator, I have learned a lot about VDI 2035 over the last few months. VDI 2035 is a standard used in Germany for water quality control. In future articles, we will look into more detail about this alternative method of water quality control to help you better your work. However, we’ll start with a quick summary of what it is all about and how Multipipe and Elysator can help you get the most from this standard.  

What is VDI 2035?  

In 2009, The Association of German Engineers (VDI) (much like the UK CIPHE) established a set of guidelines for German plumbers to follow. The guidelines looked at heating system water quality and controlling it correctly to avoid corrosion in heating systems. These guidelines mirror methods that Elysator have been using since 1970.  
The guidelines, and Elysators advice mainly looks at controlling three points:  

  1. Dissolved Oxygen content <0.1 mg/l  
  1. Electrical conductivity – <100μS/cm.  
  1. pH level to between 8.2-10  

By controlling these three points, you can ensure your water is not doing detrimental damage to system components like radiators, heat exchangers and system seals. What’s more, because of the methods used to control the three points, the work can be done without using chemicals, which can also cause issues.  
Don’t worry; you don’t have to get your lab coats on; we can help you quickly understand this. Just contact us on the details below.  

Planning can save you time and money.  

Providing you set up your system to meet the requirement set in VDI2035, then you should never have issues. However, to keep your hard work from going backwards, follow these key points to ensure your water quality does not drop 
– Sealing of the system from oxygen entry   
– Design of the pressure control system to ensure no low/ no pressure parts of the system  
– Adherence to guide values for O2 content, electrical conductivity, and pH of heating water   
– Routine maintenance   

Limitation of VDI 2035.  

In the UK, VDI 2035 is still relatively new and is not commonly recognised. There are no regulations on water control in the UK, so VDI 2035 is not an issue. As mentioned, it is a massive improvement over the BS7593 standard for water quality. But some boiler manufacturers will not recognise this improved standard (even though if they have a European presence, then the EU version strangely does).  
Although you may not have heard of VDI 2035, the guidelines are mentioned in most manuals for leading HVAC suppliers and manufacturers. This reference helps to explain why people do get confused about this subject 

Why is Multipipe interested in VDI 2035?  

We are always looking at ways of getting more out of the UFH systems we specify. By better controlling the water, we see many benefits without the use of harmful chemicals. Here are our top four reasons for wanting to promote the implementation of VDI 2035. 

  1. It matches our aim of providing the best quality UFH systems.  
  1. It’s proven to extend the life of wearable parts, i.e., valve pins.  
  1. It helps to prevent bacterial growth by controlling oxygen and PH levels—great news for UFH systems. 
  1. It helps to limit sludge and material build-up meaning there are fewer chances of blockages.  


It sounds good! I am interested to know more.  

Great! Multipipe has a new exciting partnership with Elysator, the leading provider of solutions to the VDI standards. We aim to provide an easy to use, market-leading service for water treatment and UFH systems together. All Elysator products can be used with Multipipe products. By purchasing Elysator products via Multipipe, we can help you better understand your system for the future.  
Contact Multipipe technical for more information 01245 850799 or