Heating problems
Radiators not heating or warm only at the top: causes and what to do
Cold radiators are the most common heating-season complaint. Usually it is air in the system, unbalanced flows or sludge. Below: what you can safely check yourself and when to call a specialist.
Answer in 1 working day
How to recognise it
What you see – and what it usually means
Warm only at the top, cold at the bottomsludge at the bottom of the radiator – flushing helps
Cold at the top, bubbling soundsair in the system – bleeding and restoring pressure
The furthest radiators are coldthe system is unbalanced or circulation is weak
Likely causes and the right service
You can safely check
- Check the pressure gauge (usually 1–2 bar for a cold system – see the manual).
- Check that radiator thermostatic heads and manifold valves are open.
- Note the error code and photograph the rating plate.
We do not give repair instructions: gas, electrical and pressurised systems are serviced by qualified specialists.
Smell gas? Do not switch anything electrical, close the gas valve if safe, open windows, leave and call 112.
KnowledgeRadiators not heating: the most common causesIf a radiator is warm only at the top – there is usually air in the system. If… Fault reporting
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3D
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The 3D house shows the heat source, pump group, manifolds and radiators with water flows – it is easier to understand what the technician will check.
Diagnostics3D · System flushingHeating system with flows
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