primopiano - stock.adobe.comAir trapped in radiators reduces heat output and can distort the readings of heat cost allocators. This is particularly relevant for older units or those with poor installation. Regular bleeding and professional maintenance help prevent unnecessary discrepancies.
How can you tell if there's air in the radiator?
A gurgling noise and uneven heating – especially in the upper part of the radiator – are typical signs of air in the radiator. Residents of higher floors are particularly often affected. The reason: air, due to its lower density, tends to collect in the upper part of the radiator.
perfectlab – stock.adobe.com /How does air in the radiator affect the heating bill?
Air in the radiator has several technical and billing-related consequences:
- Reduced heating output: An air cushion can reduce the standard heating output, for example from 1.400 to 1.200 watts. To still heat the room, the radiator runs for a longer period.
- Falsified consumption recording: Modern heat cost allocators are usually installed at 75% of the building's height. If there is an air gap there, the allocator registers less heat – and therefore less consumption.
- Influence of device generation: Old heat cost allocators that are 50% of the installation height are no longer permitted. Modern devices are more accurate, but can also be inaccurate if air is trapped in the measuring area.
Important: The heat cost allocator rates the radiator based on its standard output – not its actual heat output. This can lead to a difference between measured and perceived consumption.
What to do if there's air in the radiator.
A simple vent often solves the problem:
- Open the radiator during operation using a bleed key.
- Allow air to escape until bubble-free water comes out.
- Have a container ready to catch any spills and prevent water damage.
If the problem occurs regularly or persists:
- Hire a specialist company.
- Have the heating system checked for air intake or lack of water pressure.
- If necessary, refill the water in the heating system.
contrastwerkstatt – stock.adobe.comHeating bill from a professional
Brunata Minol supports you with digital measurement technology and radio transmission and in providing interim consumption information via app – secure, digital and compliant with the German Heating Cost Ordinance (HKVO).
Legal aspects
Noise from air in a radiator can be relevant under tenancy law. A ruling by the Berlin Regional Court (case no. 64 S 485/99) confirms this: Gurgling radiators in the bedroom justified a rent reduction of 7,5%. Even if the noise level was below 30 decibels, it was considered unreasonable.
Conclusion
Air in the radiator is not a billing error, but a technical problem. It affects both the heating output and the measurement of consumption. This can lead to a perceived unfairness in the heating bill – even though the actual energy consumption remains unchanged.
What should landlords do now?
- Have your radiators bled regularly – ideally at the beginning of the heating season.
- Inform residents about signs and ventilation.
- If problems occur frequently, hire a heating company.
- Ensure that modern heat cost allocators are installed at the correct height.
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