DS40 System Cleaner 1.9Kg

Product Code: 61102

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DS40 System Cleaner is a fast-acting, citric based acid cleaner designed to remove limescale, black sludge & other system contaminants.


DS40 System Cleaner is a fast-acting, citric based acid cleaner which is designed to remove limescale magnetite or black sludge and other system contaminants. Ideal for use when powerflushing it can also be used to descale a heat exchanger or boiler component separately.

  • Rapidly removes limescale, black sludge and other deposits
  • Restores circulation and improves heating efficiency
  • Free-flowing powder for easy use with powerflushing units or application via F&E tank or Injector (for sealed systems)
  • Turns yellow when product exhausted
  • Compatible with all mixed metal systems
  • Neutraliser sachets included

Product Uses

For fast-acting removal of limescale, black sludge (magnetite) and other deposits from boilers and central heating systems. Designed for use with powerflushing units for more efficient, rapid cleaning. Can be used separately to descale a boiler.

Application & Dosage

For detailed instructions on the cleaning of central heating systems using DS40 System Cleaner, please refer to the instruction leaflet inside the box. The product can be poured as a free-flowing powder directly into a powerflushing unit. Alternatively, by pre-dissolving in warm water, the product can be applied via the F&E tank or, in a sealed system, via a Fernox Injector into a radiator. One box (1.9 Kg) is usually sufficient to clean a typical domestic central heating system. For large systems and heavily scaled or sludged systems, additional powder may need to be added. During the early part of the clean, a colour change (red-yellow) indicates that the product is exhausted and more powder needs to be added.

Physical Properties

DS40 System Cleaner Colour: Red
Odour: Faint (in solution)
Form: Powder
pH: 2 – 3 (2% w/w solution)
SG: n/a

Packaging, Handling and Storage

Fernox DS40 System Cleaner is supplied in 1.9 Kg containers. DS40 System Cleaner is classified as an eye irritant. Eye protection is recommended when using this product. Refer to the product SDS for more information. Keep out of the reach of children.