What is the best boiler for a large house?

If you're the owner of or live in a large house, you need a boiler that's equipped to meet your heating requirements. Whether you have a big family or you're living in a shared house with lots of different people, your central heating system needs to be powerful enough to provide hot water/heating for multiple bathrooms, bedrooms, and living spaces.

A regular boiler might not be able to stand up to your hot water demands, meaning you will need to invest in a more powerful boiler that can heat and store hot water at a scale that enables everyone to have a hot shower.

But, with so many options out there, it's sometimes tricky to know where to start. To make it easier and help you get the best new boiler for your home, we've rounded up a list of the most efficient boilers for homes with five or more bedrooms.

What different types of boilers are there?

Before we get into the models of boilers that are best for large houses, let's take a look at the different types of boilers available to buy. Each of these has pros and cons, so it's worth doing some reading before deciding which one is right for you. After all, you don't want to have to pay out boiler installation costs more than once!

Combi boilers

Combi boilers are the most compact type of boiler, with no hot water cylinders needed. They work by connecting directly to a home's cold water supply and provide hot water on demand.

Despite being a highly efficient boiler with the added bonus of being easy to service, a combi boiler may not be able to cope with the hot water needs of larger homes. This is because there is no hot water tank in which to store volumes of hot water meaning a combi boiler will only really be able to accommodate one person showering at a time.

Ultimately, a combi boiler is generally suitable for smaller homes with less demand for large volumes of hot water in central heating systems using no more than one water outlet at a time.

Standard boilers

Also called regular, conventional standard or heat-only boilers, standard boilers are ideal for larger homes with lots of rooms that require hot water at the same time. They provide heat directly to your home's radiators and can deliver hot water to your taps from a storage cylinder.

Open-vented conventional boilers are the most common type of standard boilers. They require a feed of cold water, a hot water cylinder for storing hot water, and space above for expansion tanks.

One potential downside of standard boilers is that they aren't able to deliver instant hot water. You'll have to wait for the hot water storage tank to heat up before turning on a hot water tap, but this can be managed effectively by setting your boiler to turn on at specific times of day depending on when you're going to need the most amount of hot water.

System boilers

System boilers - sometimes referred to as closed-vent or sealed system boilers - can also be more suited to larger homes. They require a hot water cylinder, but unlike standard boilers they don't need a cold water tank in order to provide heating for your home.

This makes system boilers ideal for both medium and large homes with limited loft space as they do not require a feed and expansion tank.

The best boiler for you will depend on the number of bathrooms you have, how many people live in your home, how many radiators you have, and the overall heating efficiency of your property.

Boilers by fuel type

Gas boilers

Gas boilers provide central heating and hot water to both residential and commercial properties by being connected directly to the mains gas supply. Natural gas is used to heat water within a water tank before being pumped directly around a home's central heating system or stored in a hot water tank for later use.

Gas boilers are highly efficient and are the most common type of boiler that tend to be favoured by installers and heating engineers. This means that they should be more straightforward to repair if anything goes wrong.

Oil boilers

Oil boilers work by using a supply of oil that's stored in an external tank to generate heat and hot water for your home. Oil boilers are especially good for larger homes in rural areas, where access to the mains gas or electric grid may be restricted. If you have a large farmhouse, period property, or manor house, then an oil-fired central heating system might well be the best option.

Oil boilers can also offer high levels of energy efficiency, delivering a good return on each unit of energy used which can help to keep your energy bills to a minimum.

LPG boilers

LPG boilers use liquid petroleum gas, commonly Butane or Propane, stored in external tanks. As with oil boilers, LPG boilers are ideal for more rural properties that don't have access to the main gas supply.

An added benefit is the fact that LPG is a low-carbon fossil fuel, producing 15-20% less carbon dioxide than other fuels. You can buy combi boilers, system boilers, and standard boilers that are powered by LPG.

Greener boilers

Electric boilers and biomass boilers are referred to as greener alternatives to traditional gas-powered or oil-powered boilers as they are a low-carbon form of heating. Whether you want a combi boiler, system boiler, or standard boiler, a growing demand for sustainable central heating systems means manufacturers are providing more and more electric models.

But, while they do have the environmental benefit of reducing your carbon footprint, these types of boilers tend to be less powerful than gas and oil boilers meaning they are far better suited to smaller properties like flats or one to two-bedroom houses.

This is important to bear in mind if you're trying to select the best boiler for a large house as electric models might not be able to supply hot water for all your bedrooms and bathrooms.

What types of boilers are best for large homes?

If you need to choose a new boiler for a large property, it may be best to avoid some combi boilers, as they tend to be more appropriate for smaller to medium-sized homes. Even a large combi boiler might struggle to meet high hot water demands if there is no supplementary hot water storage cylinder in which to hold hot water for showers, baths, and washing up. 

What's more, most combi boilers won't be able to deliver hot water to multiple bathrooms or hot water outlets at once, as the rate at which water is supplied will reduce considerably. 

The best boilers for larger houses can often be standard and system boilers. Provided that they have a big enough water storage cylinder and power rating, these will be able to provide enough hot water for all of your bathrooms, radiators, and underfloor heating systems simultaneously.

Worcester Bosch, Ideal boilers and Baxi boilers are all widely considered to be high-quality, reliable manufacturers that provide a range of options to suit your lifestyle. If you're stuck on which boiler brand would be best for your home, take a look at our comparison guides, like Baxi vs. Worcester Bosch boilers or Ideal vs. Baxi boilers. 

Things to consider when choosing the best boiler for a large house

How many bedrooms and bathrooms does your house have?

For anything larger than a five-bedroom house or for homes with more than two bathrooms, the best boiler will be a system or standard boiler. If you have a seven-bedroom house or larger, even the best combi boilers are unlikely to be able to meet your hot water needs. If you don't have an attic or loft, a system boiler is going to be the best boiler for you, as standard boilers need space for expansion tanks.

How many radiators do you have?

As a rule of thumb, homes with more than 15 radiators need to think carefully about the type of boiler they install. With most homes having at least one radiator in each room, anything larger than a five-bedroom house could quickly exceed this number.

How many people live in your house?

Typically, the more people you have living in your house, the greater your domestic hot water demands will be. Families with more than five people, or families that regularly have friends or relatives around to stay might consider a system or standard boiler that has a hot water storage cylinder big enough to accommodate multiple showers at once.

Additionally, it might be worth forward-planning when choosing the best boiler for your home. If you're thinking of having more children in the next few years, it could be better to invest in a slightly more powerful boiler now so that you don't have to replace it with a new boiler as your family grows.

What are your household's showering habits?

If more than one person is going to want to shower at the same time, or if you know that people will want to take more than one shower a day, your boiler's power and hot water storage capacity will be hugely important.

If this sounds like your household, it's worth investing in a bigger, more powerful boiler that can meet your hot water demands. If you're moving into a large house with previous tenants whose hot water demands were lower than yours, it might be necessary to buy a new boiler.

Energy efficiency

The more efficiently your boiler heats up water the lower your energy bills will be. For a large house with potentially high utility bills, choosing a boiler that's as energy efficient as possible will be key. It could be a combi, system or standard boiler - but aim for one that's A-rated and more than 90% efficient.

Fortunately, it's not just the most expensive or best system boilers and standard boilers that are energy efficient - all boilers now need to be A-rated for efficiency.

Warranty period offered by the brand

The best boiler for a large house should come with a decent manufacturer's warranty. This ensures you're covered in the event of anything going wrong, so take time to explore your options before committing to one.

Brands like Worcester Bosch, Ideal and Baxi all get excellent reviews from both users and Gas Safe registered installers.