Demineralized Water for Heating Systems

Demineralized Water for Heating Systems – Benefits, Filling Procedure & Air Removal Using REMS Solar-Push

To ensure long-term efficiency and reliability of a heating system, the type of water used for filling is extremely important.
Modern heating systems increasingly recommend demineralized water, which minimizes scale buildup, reduces corrosion, and improves energy performance.

What is demineralized water and why is it the best option for heating systems?

Demineralized water is purified water with removed minerals and salts. Its main advantages include:

  • No scale buildup in heat exchangers;
  • Lower risk of corrosion;
  • Improved heat transfer efficiency;
  • Longer lifespan for the boiler and entire system;
  • Suitable for both standard heating systems and solar collector circuits.

How to properly fill a heating system with demineralized water?

  1. System preparation – check valves, fittings, expansion tank. If tap water was used previously, flushing the system is recommended.
  2. Filling – fill slowly from the lowest point while monitoring system pressure (typically 1.2–1.8 bar).
  3. Air removal – bleed the system to eliminate air pockets and circulation noise.

⚠ Important Step – Add a corrosion inhibitor

Although demineralized water prevents scale, the lack of minerals can make it more chemically aggressive to metals.
For this reason, after filling the system, a corrosion inhibitor must be added.

Inhibitor benefits:

  • Protects metal components from corrosion;
  • Stabilizes water chemistry;
  • Extends pump and heat exchanger lifespan;
  • Helps maintain maximum heating efficiency over time.

Bleeding and system activation using REMS Solar-Push

REMS Solar-Push is a professional tool designed for filling, flushing, and bleeding heating and solar systems.
It circulates the fluid in a closed loop, quickly removing air from the system to ensure stable pressure and optimal heat transfer.

With this device, system filling becomes faster, cleaner, and highly reliable — without air blockages or unnecessary stress on pumps.

💡 Final result:

Demineralized water + Corrosion inhibitor + REMS Solar-Push = a long-lasting, efficient & quiet heating system.