Washing Clothes at Lower Temperatures

Why temperature matters

In a typical washing machine, a large share of the energy goes into heating the water rather than turning the drum. Lowering the temperature of the wash therefore tends to reduce the energy used per cycle, and the effect is usually larger than most other tweaks to a single wash. How much you save depends on the machine, the programme and how your water is heated, so it is best to think of it as a general direction, not a fixed amount.

The question is whether clothes still come out clean and hygienic. For a lot of everyday laundry, the answer is yes, because heat is only one of four things that clean laundry.

The four factors in cleaning

A useful way to think about washing is that cleaning comes from a mix of:

• Chemistry: the detergent, which loosens and lifts dirt and stains.
• Mechanical action: the movement of the drum.
• Time: how long the wash runs.
• Temperature: the heat of the water.

If you lower one factor, the others partly make up for it. Modern detergents are generally formulated to work well at lower temperatures, which is why many are labelled for 30 or 40 degrees. A cooler wash with enough detergent and a longer cycle can clean about as well as a hotter, shorter one for ordinary soil, though results vary by product and stain.

For this reason, switching from a high-temperature wash to a cooler one often goes unnoticed for lightly or moderately soiled clothes. It is worth trying a cooler setting for a few loads and checking the results.

Detergent matters

Using the right detergent in the right amount makes a cooler wash work. Some points to keep in mind:

• Use a detergent that is designed for lower temperatures, and read the label for dosing guidance.
• More detergent does not mean cleaner clothes. Too much can leave residue on fabric and in the machine. Dose according to load size and how hard your water is.
• Powders can be less effective at low temperatures if they do not fully dissolve, while liquids may dissolve more easily. Check what suits your machine.
• Pre-treating stains, with a stain remover or a soak where appropriate, often works better than a hotter wash.
• Concentrates and refills can reduce packaging. If you are comparing options, our points about eco-friendly cleaners and cleaner refills can help you think through the trade-offs.

Always check the care label on each garment first. It tells you the maximum temperature the fabric can take, and going cooler is generally safe.

When hotter washes are still advised

Cooler is not right for every load. There are cases where higher temperatures, or a specific disinfecting step, are recommended.

• Illness in the household. If someone has an infectious illness, official health guidance may advise washing bedding, towels or clothing at a higher temperature or with a laundry sanitiser. Follow the advice of your local health service rather than general tips.
• Items that are heavily soiled or in close contact with the body, such as cloth nappies, underwear, towels and bedding. Some people choose a hotter wash for these periodically, particularly when someone is unwell or has a skin condition. Check care labels and the guidance for specific products.
• Allergy management. Advice for dust mite allergy often includes washing bedding at a higher temperature. If this applies to you, ask a health professional what is appropriate.
• Food-contaminated cloths. Kitchen cloths and tea towels are often washed hotter, and replaced regularly.
• Product or manufacturer instructions. Some items and detergents specify a temperature. Follow those.

The difference between simple cleaning and disinfection is worth understanding. A normal wash removes most dirt and many microbes, but only heat or a specific disinfecting agent is designed to reduce them further. Our explainer on disinfecting versus cleaning covers when each is appropriate, and it is not needed for ordinary day-to-day washing.

Looking after the machine

A habit of always washing cool can allow detergent residue, grease and bacteria to build up in the drum, seal and drawer, which can cause smells. Many manufacturers suggest running an occasional hot cycle with the drum empty, or using a machine-cleaning product, and cleaning the door seal and filter regularly. Leaving the door and detergent drawer open between washes lets the machine dry. Follow your manual for the programme and product it recommends.

If your water is hard, limescale can also affect how well detergent works and how a machine performs over time. Adjusting your dose and following descaling advice may help.

A sensible approach

1. Check the care label and the soil level.
2. Choose a lower temperature for everyday loads, and use a detergent designed for it.
3. Pre-treat stains instead of defaulting to heat.
4. Save hotter washes for situations where hygiene or health guidance calls for them.
5. Run a periodic maintenance wash and keep the machine ventilated.

Washing cooler is one of the easier changes to home energy use, and it fits well with running full loads and drying on a line when you can. It is not a rule that applies to every item or situation, so use judgement and follow health advice where it matters.