Do washing machines in the UK use hot water from the boiler?

Do washing machines in the UK use hot water from the boiler is a question that we as a plumber Bristol are often asked. In short, no! Modern machines that you buy from the shop will heat the water internally so a hot connection is not required like unlike some older machines.

You can see on the back of the machine if there is a red and blue connection or blue (cold) only.

But there is a longer answer if you really want to know it all…

washing machine


When it comes to the convenience of modern life, washing machines are an absolute blessing. Gone are the days of hand-washing clothes, as these machines have revolutionized the way we do laundry. But have you ever wondered how they actually work when it comes to water temperature? Do washing machines use hot water from the boiler, or do they heat it themselves? In this article, we will delve into the inner workings of washing machines and answer this intriguing question.

The Basics of Washing Machine Operation

How Does a Washing Machine Work?

To understand whether washing machines use hot water from the boiler, it’s essential to grasp the fundamental mechanism of these appliances. A typical washing machine has two main compartments: one for washing and one for rinsing. Each compartment is filled with water at different temperatures, depending on the selected wash cycle.

Types of Washing Machines

Before we delve into the specifics of how washing machines heat water, it’s worth noting that there are two primary types of washing machines: top-loading and front-loading. The type of machine can impact the way they handle water temperature.

The Role of Hot Water in Laundry

The Importance of Hot Water

Hot water plays a crucial role in effective laundry cleaning. It helps to dissolve detergents and stains more efficiently, ensuring your clothes come out fresh and spotless. But where does this hot water come from?

Cold Water Washing

In recent years, there has been a growing trend toward cold water washing. Many washing machines now have dedicated cycles for cold water washes. This has led to the misconception that washing machines no longer use hot water from the boiler. However, this isn’t entirely accurate.

How Washing Machines Use Hot Water

Mixing Valves

Most washing machines are equipped with mixing valves. These valves allow them to combine hot and cold water to achieve the desired temperature for the selected wash cycle. This means that even when you choose a cold water wash, a small amount of hot water might still be used to achieve the optimal temperature for cleaning.

The Boiler Connection

Now, let’s address the main question: do washing machines use hot water from the boiler? In many cases, yes, they do. If your washing machine is connected to both hot and cold water sources, it will use hot water from the boiler when you select a warm or hot wash cycle.

Self-Heating Washing Machines

However, some washing machines are designed to heat water internally using an electric heating element. These machines are more energy-efficient but are less common than those that rely on your boiler for hot water.

Energy Efficiency Considerations

Pros and Cons

Using hot water from the boiler has its advantages and disadvantages. On the one hand, it can be less energy-efficient, as it may require more energy to heat water to the desired temperature. On the other hand, it can be faster since the hot water is readily available.

Energy-Saving Tips

If you’re concerned about energy consumption, you can take steps to optimize your washing machine’s efficiency. Using cold water cycles for lightly soiled clothes and choosing energy-efficient appliances can help reduce your environmental footprint.


In conclusion, washing machines can indeed use hot water from the boiler, especially if they are equipped with hot and cold water connections. However, some machines are designed to heat water internally. The choice ultimately depends on the make and model of your washing machine. Regardless of the method, the goal is always the same: clean, fresh clothes.

Frequently Asked Questions

  1. Can I use hot water exclusively for laundry? Yes, you can, but it may not be the most energy-efficient choice. Using a mix of hot and cold water is generally more balanced.
  2. Do front-loading washing machines use hot water differently than top-loading machines? Front-loading machines tend to be more water-efficient, which can impact the way they use hot water. However, the fundamental principle remains the same.
  3. Are self-heating washing machines better for the environment? Self-heating machines can be more energy-efficient in the long run, making them a greener choice.
  4. Can I install a self-heating system in my existing washing machine? It’s possible in some cases, but it’s best to consult with a professional to determine if it’s feasible for your specific machine.
  5. What’s the best temperature for washing clothes? The ideal temperature depends on the type of fabric and the level of soiling. For most loads, a warm or cold wash is sufficient, as it conserves energy while still cleaning effectively.

Do washing machines in the UK use hot water from the boiler?
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