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Last updated on May 15th, 2024 at 09:04 am

When it comes to choosing a boiler for your house, there are lots of factors to consider. Choosing the right size boiler can help you save money and energy for the future and can last for up to around fifteen years. It can be overwhelming with the various boiler types available but luckily our team at Warmable is here to break it down for you.

How to Choose the Right Size Boiler for your Home

The right size boiler will vary from home to home depending on the size of the property and your heating and hot water needs. A good way to look at it is to consider how many radiators you have in your home and the number of bathrooms. It’s important to get a boiler that’s the right size for your needs so that you’re not spending unnecessarily on your energy bills.

What are the Different Types of Boilers for a House?

Before choosing boiler size, you should choose the type of boiler you choose to heat your home with. There are various types of boilers on the market, each with their own range of benefits and efficiencies. Depending on various factors, such as your current boiler system or the amount of space available, there will be a certain type of boiler better suited for your needs.

Combi Boilers

In UK homes, one of the most common boiler types is a combination boiler, or combi boiler. This type of boiler doesn’t store hot water but rather heats hot water as and when it’s needed. The combi boiler features a water heater and a central heating boiler in one unified system, staying on standby until hot water is needed and then heating it in an instant.

The downside of combi boilers is that they can only support one outlet at a time – that is, either for heating or hot water. For larger properties with multiple water outlets, a combi boiler is probably not the best option.

System Boilers

A system boiler takes ist water directly from the mains and heats it in a storage cylinder. Unlike other boiler types, a system boiler doesn’t require a cold water tank. Ideal for larger properties with a high hot water demand, system boilers can provide instant access to hot water at two or more outlets at a time, without sacrificing the water pressure.

Choosing the Right Size Boiler for Your Home

The more radiators your home has, the more powerful your boiler will need to be

Conventional Boilers

Conventional boilers, also known as ‘standard’, ‘regular’, ‘traditional’, or ‘open-vent’, rely on hot and cold water tanks to heat water. Using fuel to warm up the water, typically gas or oil, the water is then transported to the hot water tank via a pump. Once your heating or hot water is turned on, this hot water will travel to your taps and radiators. A cold water tank will carry water from the mains to a hot water cylinder. As these boilers can store large quantities of hot water ahead of time, they are good for larger houses with high demands for heating and hot water.

What Size Boiler Should I Choose?

Once you’ve chosen your boiler type, you need to choose the correct size according to your home’s heating requirements. Factors affecting boiler size include the number of: bedrooms, radiators and bathrooms.

Number of bedrooms Number of radiators Number of bathrooms Recommended boiler size
1-2 0-10 1 24-27kW
3-4 10+ 2-3 28-34kW
4+ 20+ 3+ 23-43kW

How much does it cost to run a boiler?

For electric boilers, the average running cost for a boiler in the UK is anywhere between £500-£1,500 and a cost per hour of about 10-20p.

To calculate the running cost of your gas boiler, you need to multiply the kWh of your boiler by the price of 1kWh of gas, then divide it by 100. For example, if your boiler uses 20kWh of gas per house, and your gas costs 11.2p, it would be 20 x 11,2 = 224, divided by 100 = £2.24 per hour to run your gas boiler.

Thus, the smaller the boiler size, the cheaper the running costs. However, you need to think about your home’s hot water needs and assess what is realistic.

Closing Thoughts

When choosing the right size boiler for your house, you need to think about whether a combi, system or conventional boiler is right for you. Combi boilers are a popular boiler choice for the majority of UK homes and their large power output means they can heat water on demand. You also should consider whether you need a gas or electric boiler. Depending on the number of bedrooms, bathrooms and radiators in your home, you may need a different size boiler.

Wherever you’re based in the UK, Warmable can help you get a boiler installed within 24-48 hours. With access to over 1,000 Gas Safe Registered Engineers, we can get you the best quote to suit your needs. Arrange an installation with us today, or arrange a no-obligation free initial visit and consultation. Contact us today!

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