Boiler Size Matters: How to Choose the Right Boiler for Your London Home

Choosing the right boiler can make a huge difference in your comfort and in how much you spend on heating over the long run. But how do you find the right size boiler for your London home?

Our experts at WPJ Heating can help you select the perfect size boiler for your property. In this blog, we talk about the essential information you need to make an informed decision about choosing a correctly sized boiler for your London property.

Why boiler size matters

Boiler sizing isn’t about physical measurements. Of course, you need the boiler to fit in your space, but the most important factor is its energy output, which is measured in kilowatts (kW).

Think of kilowatts as a measure of heating power — a higher kilowatt rating generally indicates a larger boiler. An undersized boiler will struggle to heat your home adequately, while an oversized boiler will waste energy by constantly cycling on and off, unnecessarily increasing your heating costs.

What’s in a kilowatt?

A kilowatt represents 1,000 watts of power. For example, a 40kW boiler has the capacity to generate 40,000 watts of power per second to heat your water.

Understanding the difference between sizes

Combi boilers typically have higher outputs to provide instant hot water on demand. Heat-only and system boilers generally have lower outputs because they heat water more slowly and store it in a cylinder for later use.

Size impacts a boiler’s cost and efficiency.

The right boiler size to choose really depends on the size of your London. Larger homes generally need higher kilowatt outputs, but don’t worry —newer boiler models are much more energy-efficient than older ones, helping you save money on your heating bills.

Choosing an adequately sized boiler for your London home

The number of bedrooms, bathrooms, and showers will determine the ideal boiler size for your home. For example, homes with two to three bathrooms often find that a conventional or system boiler with a 200-litre hot water cylinder is sufficient to meet their average hot water demands.

Space requirements

It’s also important to consider how much space you have for the installation. Each boiler type has different space requirements, especially if it needs a hot water cylinder. Combi boilers don’t need a cylinder, so they require only 0.5 to 1 square metre of space. System boilers have a hot water tank, so they need at least 1.5 to 2 square metres of installation space.

Are you installing a conventional boiler? Make sure to allot 2 to 3 square metres to accommodate the cold water storage tank and hot water cylinder.

Understand your hot water demand and household size

Combi boilers may suffice for households with low hot water demand, making them suitable for small homes with 1 or 1.5 bathrooms. Larger households with 2 or more bathrooms will find conventional or system boilers to be more cost-effective and reliable in meeting their high hot water demand.

What happens if you get the wrong boiler size?

Getting a boiler that’s too big for your home can actually cause more problems than it solves. An oversized boiler produces more heat than your home needs, which means energy waste and higher utility bills. On the other hand, an undersized boiler simply won’t be able to keep up with your demands.

Our experts can help!

Let our Gas Safe Registered heating engineers eliminate the guesswork from sizing your boiler. Call us at 020-7350-2511 to book your appointment or arrange for an instant boiler quote. We at WPJ Heating are accredited by top boiler brands like Worcester Bosch, so you can trust our expertise and recommendations.