Sludge separator with magnetite

  • how exactly does the sludge seperator work?
  • why is my heating water contaminated?
  • is a sludge seperator necessary?

The sludge trap or also called sludge separator is probably one of the most important components to keep the heating water clean. Ensuring the cleanliness is important, because contaminated water can lead to serious problems in the long term. To save you from a bad surprise in form of a high bill, we want to introduce you to the sludge separator in this article.


Source: Buderus-thermotechnik

Functionality of the sludge separator

The sludge separator cleans the heating water from sludge and metallic substances. It is equipped with a spiral inside which reduces the speed with which the water flows through the device and makes it possible for the heavier particles to settle. In addition, a sludge separator may be equipped with a magnet that pulls out the metallic substances. The sludge is deposited in a separate chamber and must therefore be cleaned regularly. In the past, filters were installed to clean the water. However, these not only reduced the flow rate, but also the pressure, which leads to malfunctions in operation. Furthermore, maintenance is usually much more costly.

Reasons for contaminated heating water

Contamination of heating water is quite normal, at least to a certain extent. In the long term, the water forms lime, which over time leads to the formation of sludge. Air entering the heating system also causes additional sludge. The air reacts with the metals that the individual components are made of and forms rust. The oxygen is broken down in the process, but the rust gets into the water.

Do I need a sludge separator with magnet?

Sludge removal is neglected in many heating systems in Germany. Sludge continues to circulate in the heating circuit, settling on seals and in radiators and clogging pumps. Radiator performance is reduced, which can lead to higher costs and less comfort. The clogged seals no longer allow water to flow reliably and can be damaged, and a clogged pump can even lead to a total loss in the worst case. Therefore, you should definitely have a sludge separator installed, whether old or new construction.


A sludge seperator is definitely recommended. In the best case a model with magnet. Most of the particles that cause contamination are collected and prevented from causing major damage. Regular maintenance should not be neglected. If an unusually high sludge formation can be determined, it is absolutely necessary to look for the cause, because in the long term even the sludge separator cannot stop the wear of other parts. Sludge traps are available for as little as 50€.

Autor: Jan Bittner