What Are the Best Boilers of 2024?

How to Find the Best Boilers for You

Before considering what the best boilers of 2024 are, it’s important to ask a few questions to understand what kind of boiler you would need.

• What’s the budget?

• How many bedrooms do you have?

• What space do you have for a boiler?

• Are you connected to the gas grid?

• Have you considered any eco options?

The more bedrooms you have, the higher your hot water demand will be, so the best boilers are the right size. Generally, bigger boilers will need more room to compensate for this high use. Conversely, if you only have a small home, you may be able to simply install a combi boiler instead.

When it comes to understanding the power consumption you’d need from your boiler, best practice is to follow this rule of thumb:

• Fewer than 10 radiators: 27kW boiler

• 10–15 radiators: 28–34kW boiler

• More than 15 radiators: 34kW boiler

Factors to Consider When Choosing Best Boilers

When it comes to picking the best boilers, there are a few things to consider. Above all, you want reliability, longevity and value for money. You should also check the warranty period as this gives you the reassurance that you will be covered should something ever go wrong. Even the best boilers from a trusted brand will have all of these.

Here is what to look out for when shopping for boilers on the market:

• A decent warranty offered by the brand

• The overall brand reputation

• Trustpilot reviews

• Awards

• Customer service rating

• How much a new boiler costs

• Efficiency rating

The Different Types of Boiler

• Combi

• System

• Heat only

Combi Boiler

A combi boiler provides both your heating and hot water from a single unit on demand. It’s quite compact and is usually mounted on a wall in your home. As they’re smaller, they’re not suitable for larger homes and would struggle with the demand of a four or five bedroom house.

Some of the best boilers in this category feature their own mini hot water storage, to get around a higher water demand. The Combi Boiler Guide provides further details.

Pros

• Space saving

• Energy saving

• Compact

If you don’t have room for a hot water tank or cylinder, the best boilers for you might be combi boilers. Heating up water as and when you need it, they can save on energy and space. Mains water passes through a heat exchanger that rapidly warms it up for use.

The water is only heated up when you need it, which saves on setting heating up times and the extra energy that is needed from this process. As a result, your energy bills will be lower.

Due to their compact size, combi boilers are easy to install. Smaller properties can benefit from them much more without compromising on space.

Combi boilers are available in oil, gas and electric models. This means the best boilers can be installed to any property, even ones not connected to the gas network.

Cons

• Reduced flow

• Lower output

• Relies on mains pressure

• No immersion

One of the main disadvantages of combi boilers is that water flow can be reduced if two or more outlets are being used at the same time. A larger property with several bathrooms that will be used simultaneously will struggle with a combi boiler. Likewise, they only work on mains pressure, so even the best boilers can’t work with power showers.

There is also no backup supply of hot water, which means no immersion heater either. If you need a lot of hot water at once, a combi boiler will be unable to provide this. In the event of a boiler breakdown, a combi boiler cannot continue to run with the help of an immersion.

Heat Only (Regular) Boilers

Popular and abundant in older, larger homes, regular boilers make use of a header tank in the loft to maintain a set pressure. They store hot water for later use in a cylinder but take up more space than the common system boilers in use today.

Originally considered the best boilers to have in a home, heat only boilers were the modern way for homes to heat both a tank of hot water and central heating. Larger homes with more hot water demand can make use of these kinds of boilers without having to worry about running out of hot water.

Pros

• Strong flow rate

• Suitable for low pressure areas

• Large hot water storage capacity

• Still available after breakdown

As the pressure for the heat only boilers is produced artificially using a header tank in the loft, these boilers have a strong flow rate. This makes them ideal for households with a bigger hot water demand across multiple bathrooms. It also means they are the best boilers for low pressure areas as some older systems might not cope with higher pressures without being replaced.

With the hot water storage tank, heat only boilers can keep up with demand with a bigger storage capacity. Hot water will be ready for when it’s needed and space heating through radiators can be achieved at the same time. An immersion heater can still give you hot water in the event of a breakdown.

Cons

• Extra space needed

• Can run out of water

• Less efficient

Once the hot water tank runs out, a heat only boiler needs to be refilled and reheated before you have hot water again. If you need a lot of hot water on a regular basis, a heat only boiler may not be the best boiler for you. In this instance, you’ll have to wait until hot water is available again.

Conventional boilers are also less energy efficient than combi boilers. Stored water is constantly heated, whereas combi boilers only heat water on demand. In terms of energy efficiency, the best boilers have a low environmental impact.

Finally, more space is needed to install a regular boiler. The header tank needs to be installed above the hot water cylinder, which limits the options you have when it comes to having it fitted. Without this extra space, the best boilers for you might be the alternatives.

System Boilers

The most modern kind of boiler, system boilers are similar to heat only boilers but take water directly from the mains instead. Consisting of a boiler and a separate hot water storage cylinder, they heat up water that is topped up from the mains. These are the best boilers when it comes to pressure they can include an internal pressurising system.

Just like traditional boilers, system boilers can produce hot water when needed for both central heating and for bathroom use.

Pros

• Suitable for high hot water demand

• More compact than heat only boilers

• Compatible with solar power

As system boilers store the hot water they heat, these are the best boilers for large hot water demands in households. They also work on mains pressure, so there’s no need for a header tank to be installed in the loft to help the system along. This is good for space saving and to prevent frozen pipes in the winter.

Solar power can be used to either provide the electricity to heat your hot water or to heat up the water itself. Solar photovoltaic panels can run the immersion heater, which can save money on your energy bills. Solar thermal technology can warm hot water in external pipes under the heat of the sun. Both examples save you money.

Cons

• Not as efficient as combi boilers

• Hot water can run out

• Not as space saving as combi boilers

While system boilers produce larger quantities of hot water, combi boilers are the best boilers in terms of saving space and not running out of available water. Similar to heat only boilers, once the hot water has been used from the cylinder, it will have to be heated up again before being available.

Older properties may not be compatible with water being provided at mains pressure, unless pipework is replaced. Also, as a hot water cylinder is necessary for a system boiler, if you don’t have the space for it, a system boiler won’t be the best option for you.

Condensing Boilers

Condensing boilers are efficient and most commonly found in newer homes across the UK. They make use of a flue recovery system which captures heat from expelling gases and uses it to heat water that’s entering the system. They are more environmentally friendly and come in gas and oil types. In terms of newer gas systems, condensing systems are the best boilers you can get.

Alternatives to Boilers Not on the Gas Grid

It’s estimated that around 2.7 million homes aren’t connected to the gas grid network. The best boilers for these homes will be some of the alternatives listed below.

• Oil

• Wood burners

• Biomass

• Electric

Oil boilers have been around for a long time, but their environmental impact makes them difficult to choose. Wood burners are a more sustainable alternative but generally have more maintenance involved. If you don’t mind a little effort, they could be the best boilers for you.

Biomass boilers are eligible for the government’s Boiler Upgrade Scheme, which gives you £5,000 off a new system. They are much bigger than other types of boiler and you will also need fuel storage. Electric boilers, on the other hand, are much more compact and work off the mains electricity.

From 2035, gas boilers may not be installed in new build homes. Here's everything you need to know about the gas fired boiler ban.

The Best Boiler Brands

When buying the best boilers, you’ll want to make sure it’s from a trusted brand and supplier. Manufacturers are often given awards for their products, which is a great advocate for their boilers.

Viessmann Boilers

Viessmann boilers have been awarded a Which? Best Buy Award on several of their best boilers. The manufacturer aims to provide future-proof heating systems that will last for many years.

Ideal Boilers

Professing themselves as the UK’s leading heating manufacturer, Ideal boilers have become a familiar British brand in the boiler industry. This manufacturer offers hydrogen blend boilers, which will come in useful for the gas boiler ban.

BAXI Boilers

Having been manufacturing since 1866, BAXI offers a range of some of the best boilers on the market. The company also has an award winning customer service team.

The Rest of the Best Boilers

Worcester Bosch Boilers

Worcester Bosch has been awarded the Which? Best Buy Award for their combi boilers for the 13th time. They also offer a 12 year guarantee, making them one of the best selling and most trustworthy brands.

Vaillant Boilers

Identifying themselves as one of the world’s leading manufacturers of environmentally friendly heating and cooling technology, Vaillant is another British brand that has seen its share of Which? Best Buy Awards in its time.

Best Boilers on the UK Market Compared

You can see an overview of the best boilers on the market in the graph below, followed by a detailed breakdown for each model.

The comprehensive list of what to look out for and the detailed breakdown of the best boilers of 2024 should give you a good idea of how much you are likely to spend replacing your current heating system. If you wish to compare quotes from local suppliers now, fill in your details using the button below to get started.