Drying laundry on radiators: damp, mould and higher heating bills

When laundry dries slowly in autumn and winter, many people hang it on a radiator. According to a Polish Express article published on 31 October 2026, this habit can harm both the building and the health of those living in it.

Where the moisture comes from

The article says a full washing machine load holds 2 to 3 litres of water after washing. When wet fabrics lie on a hot radiator, that water evaporates quickly into the room's air. The author says humidity can rise by as much as 30–40%.

If windows are rarely opened, the vapour condenses on the coldest surfaces: windows, wall corners and the areas behind furniture. The result can be peeling paint, soft plaster, swelling laminate flooring and black mould. Repairing such damage can be costly.

The general link between drying clothes indoors and condensation is also confirmed by NHS practice information (Springhill Practice), which lists drying laundry indoors, alongside cooking and bathing, among everyday activities that cause condensation.

Effects on health

According to the article, mould spores can cause chronic sinusitis, coughing, recurring bronchitis and throat problems. For people with allergies and asthma they are a strong trigger for breathlessness. For people with weakened immunity, such as children and older people, the author points to the risk of aspergillosis, a lung infection that needs specialist treatment.

The NHS practice also notes that moulds produce allergens and irritants, and can cause allergic reactions, breathing problems and asthma attacks.

Higher bills

Polish Express argues that clothes on a radiator act like a curtain: the radiator mainly heats the laundry rather than the room. A sensor or thermostatic valve may misjudge the situation, and a cold room encourages people to turn the radiator up further. As a result, energy use rises.

How to dry laundry in winter

The author considers a tumble dryer the best, if most expensive, option, as it releases little vapour into the surroundings. He advises not leaving it on overnight and checking the safety of Hoover and Candy models. He recalls an earlier case in which, after a house fire that the source says was caused by a Hoover dryer, a father and his 9-year-old daughter died; a coroner issued a fire-safety warning for models from these brands.

The problem particularly affects old houses with poor ventilation, but according to the article, modern, airtight buildings are also at risk, as they need well-working, regularly switched-on mechanical ventilation.

What this means for you

Many people in the UK live in rented flats and houses where ventilation can be limited and windows stay shut during the heating season. It is worth ventilating regularly and not covering radiators. If mould appears anyway, it is a good idea to report the problem to the landlord or property manager. If you have breathing symptoms, speak to your GP.