Boiler Replacement

Combi Boiler For A Larger House [Is It Suitable?]

If you live in a house with 4 or more bedrooms and more than 1 bathroom, it is considered a larger home.

Choosing the correct size boiler is key to ensuring you have an energy-efficient system that works effectively in your larger home…

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Combi boiler

The official term for a combi boiler is ‘combination boiler’ because of the way the system is designed. This boiler has a water heater and central heating system inside the compact unit, so you will not need to install a water storage tank.

Water is fed from the mains meaning the water pressure is better and you don’t have to wait for the water to be heated.

The main benefits of a combi boiler are:

  • You will save space inside your home.
  • As the water is heated instantly, you use less water which is better for the environment.
  • Better for properties that have minimal space.
  • There is less pipework in your home.
  • They are energy efficient.

What is a larger home?

It may seem self-explanatory, but knowing if your house qualifies as a larger home can help you make the most cost-effective decision when installing or replacing your boiler.

The kW output of a boiler determines its power; the higher the kW the more powerful the boiler will be.

Generally, if you have a home with 4 or more bedrooms and multiple bathrooms you have a larger home and you will need a larger combi boiler.

Smaller homes with less than 3 bedrooms and fewer occupants will suit a smaller, less powerful boiler.

Combi boiler for a 4-bedroom house

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What kind of output is necessary for a larger house?

If your home is medium to large, you generally have 2 options when it comes to combi boiler power output.

  • If your home has 3 to 4 bedrooms and 1 -2 bathrooms, it would be considered a medium to large property. For this type of home, a 28-34kW boiler would be suitable.
  • Larger homes with 5 or more bedrooms and multiple bathrooms would need a 35-42 kW boiler, to meet the hot water and heating demands of the household.

It is important to know that combi boilers may struggle with running multiple hot water points at once. If you have a high demand for hot water, a higher kW boiler or system boiler may be better for you.

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How many radiators do you have?

Another point to consider is the number of radiators you have in your home. Take a moment to count them to give you an idea of the kW output needed for your boiler.

This guide will give you an idea of which boiler will be suitable for you.

  • Up to 10 radiators: 24-27 kW boiler;
  • 10-15 radiators: 28-34 kW boiler;
  • 15-20 radiators: 35-42 kW boiler.

Should I choose a combi boiler or is a system boiler a better option?

If you have a high demand for hot water, a system boiler is another option. A system boiler is similar to a combi-boiler as it takes water directly from the mains, however, it stores hot water in a tank.

System boilers are good for larger properties, but the tank will take up space inside your home.

A qualified boiler installer will be able to advise you on which boiler system will be the best option.

Here are a few of the benefits of a system boiler:

  • The tank can be stored in a loft or airing cupboard.
  • It can keep up with high hot water usage.
  • They are easy to install.
  • They can work with solar panels.

Storage combi boiler for more hot water

As a balanced between a combi and system boiler, a storage combi boiler is a great option. A storage combi boiler has a hot water tank inside the unit, so you have a stored supply of hot water as well as heated water from the mains.

If you use a lot of hot water but have limited space, this type of system will benefit you.

Best combi boiler models with an output between 28 – 40 kW

Below you’ll find a list with boiler models with an output between 28 and 40 kilowatts.

The prices listed are a guide and exclude installation costs.

Baxi EcoBlue Advance 40

This combi boiler has a hot water output of 40 kW and a central heating output of 40 kW. It is a powerful combi suitable for larger homes. It is A-rated and comes with a 10-year warranty.

  • Price: An average £1,350;
  • Energy efficiency: 92%.

Baxi EcoBlue Advance 40 Combination boiler

Vaillant EcoTEC Plus 938

This Vaillant boiler is best for homes with more than 1 bathroom or an en suite. It comes with an integrated water storage tank and has hot water output of 38 kW, and central heating output of 31 kW.

The price for a Vaillant EcoTEC Plus 938 is around £1,750

  • Price: An average £1,750;
  • Energy efficiency: 89.5%.

Vaillant EcoTEC Plus 938

Worcester Bosch Greenstar 38CDi Classic

Worcester Bosch is a trusted brand with high-quality models. The Greenstar 38CDi boiler has a hot water output of 38 kW and central heating output of 30 kW, so suitable for a larger home.

  • Price: An average £1,750;
  • Energy efficiency: 92.5%.

Worcester Bosch Greenstar 38CDi combi boiler for a larger home

Ideal Vogue Max C40

This model is compact and energy-efficient. The hot water output is 40 kW and the central heating output is 32 kW. It also has an impressive 12-year warranty.

  • Price: An average £1,375;
  • Energy efficiency: 93%.

Ideal Voue Max C40 combi boiler

What are the installation costs of the larger combi boilers?

The average installation cost for a combi boiler with a higher output is between £450 to £850. These costs are without the combi boiler itself.

What are the total costs?

So for example the total costs (labour and larger combi boiler) of a Baxi EcoBlue Advance 40 are (£700 + £1,350) £1,350.

Get quotes from boiler installers

A qualified installer is required to install a boiler in your larger home.

You can find a boiler installer this by using Warmerinside’s free quotation service, where you can compare costs and choose the best boiler installer for you.