Disturbing noises emanating from the heating system can have various causes. In order to prevent them, it is advisable to inspect the system before the heating period. If, however, noise still appears in the central heating pipes, in many cases we can deal with it ourselves - without the help of professionals. Here are some of the most common causes of noise in central heating pipes and some tried and tested solutions.

Heating system clogging - causes and effects

The most common cause of noise in central heating pipes is air entering the system and interfering with its operation. For the installation to work properly it should be filled with water, not air.

The result of a vented system is noises and whistles that can be heard by the occupants of the house. It also results in radiators that do not heat at all or are only half cold, as well as noisy circulation pumps. In the case of steel pipe installations, corrosion may occur and the system may subsequently leak.

Noise in central heating pipes. - How to bleed the central heating system?

If our installation is equipped with automatic vents their function should be checked. This is because it can happen that the air vents are damaged and do not work properly, with the result that a large amount of air collects in the system. To check if an automatic valve is working properly, remove the cap from the valve and press on the needles with a thin wire. If it is working properly, water should flow out of it. Manual valves work similarly. If you unscrew an unvented system, water will flow out, in a vented system there will be a hissing sound.

Pipe noise - exceeding the permissible velocity of fluid flow in the system

Another cause of nuisance noises in the central heating system can be too high a pumping speed. It is very important to calculate the water flow rate correctly before installing the system. Exceeding these standards results in a destabilisation of the pressure in the system and thus in audible noise. In addition, increased water pressure occurs in the system when we shut down or reduce the operation of certain radiators. In such a situation, water flows through the remaining valves at a much higher pressure than before. The solution to this problem is to reduce the capacity of the pump.

Contamination or decalcification of central heating system components

The cause of excessive noise in the system can also be dirt and limescale deposited on individual system components. The heat exchanger can become both dirty and calcified. This is most common in homes with hard water. The pH of the water and its temperature also play a role, facilitating the build-up of deposits. It is then necessary to use special chemical agents to clean the system. In order to prevent contamination of the installation's components, treated water should be used for filling. Tap water contains deposits of calcium, iron and other elements, which considerably shorten the service life of the system. Other factors causing contamination of the installation include dust and dirt produced during renovation, as well as grease from the sealing pastes used to join the pipes.

The effect of a stained or contaminated installation is to increase the time it takes for the water in it to heat up. Impurities act as a kind of insulating layer, making it difficult to obtain the right temperature level. As a result, the heating process requires more power and is therefore more expensive and less environmentally friendly.

As you can see, there is no single cause of noise in the central heating system. In addition to those discussed above, there are a number of faults and mistakes made during the installation of the heating system that we are unable to deal with ourselves. If venting the radiators, regulating the pressure in the system and cleaning it with special agents do not bring about any improvement, a service technician should be contacted.