Article

Noise in the heating system

Heating system noise is a common and frustrating issue for installers and home owners alike. There are multiple potential sources of noise. Hydronic systems easily transport the sound and vibrations and it can be difficult to identify the source.


Identifying and solving heating system noise

Main causes of noise:

  • Incorrect commissioning - caused by system often operating at a higher flow than needed.
  • Lack of balancing or incorrect commissioning of the entire heating system.
  • Incorrect dimensioning of system components - for example pipes are not sufficiently dimensioned for the required flow and this will create friction noise in pipes and valves.

Other common reasons:

  • Air in the system which might result in hammering noises from pipes and  valves, often occurring when parts of the systems are replaced.
  • Resonance noise due to the pump running at the same frequency as the natural frequency of the heating system and the noise is born by the pipes.
  • Cavitation noise due to the incorrect amount of pressure due to faulty expansion vessel in the system or because all vales are cloed.
  • Impurities in the pump or on the raditor valve cones.

The good news is, there are solutions and ways to make your customers happy.

How to quieten noisy heating systems

You need to design the system, dimension and commission the heating system correctly. But how? One solution is to select the right circulator that can be set in the correct control mode or automatically adapted to the system. You can use the circulator to balance the heating system, and remove uneven flow and pressure, which will minimise the risk of noise. Grundfos ALPHA2, ALPHA3 and UPM3 GO Balance will help you do this.


All Grundfos circulators are tested in our dedicated sound laboratory. As well as being tested for noise levels according to the ISO 3745 standard , they’re also tested for how they are perceived when installed in a boiler and the entire heating system. But no matter how well-tested our pumps are, it’s impossible to fully replicate the diversity of the real-world installation. Therefore you play a crucial role in ensuring your customers enjoy a more comfortable, well-heated home.

Let’s make better heating systems together!