New Boiler Prices & Replacement Costs

Boiler Replacement Costs

The process of buying a new boiler replacement can be daunting at first. What type of boiler do you need? Which is the best boiler brand? How much does a new boiler cost? How do you find the best boiler prices?

Luckily, new boiler replacement is our favourite subject here at Boiler Guide! Here we take you through the big decisions you need to make and what you can expect in terms of the cost of new boiler installation.

Do you need a boiler replacement?

How much does a boiler replacement cost?

How to choose a new boiler

Which are the best boiler brands?

What happens during a boiler replacement?

Getting the best deal on a new boiler

Do you need a boiler replacement?

If you’re considering a replacement boiler then there’s a good chance that you’ve already noticed at least one of the signs that you need a new boiler. Here are the biggest signs that you should be considering a boiler replacement:

  • It would make more financial sense to invest in a new boiler than to have your existing boiler repaired.

  • Your boiler was installed more than 8 years ago. Boilers have an average lifespan of 10-15 years but can often start to lose efficiency after 8 years. If your boiler is approaching this age, it could be best to replace it before it breaks down and you’re left without heating and hot water. Old boilers are also less efficient and may be making your heating bills unnecessarily expensive.

  • You are unhappy with where your boiler is located in the home. Moving a boiler can be costly and it may not cost much more to upgrade to a more energy efficient model at the same time.

  • The boiler doesn’t produce enough hot water to heat all of your radiators and hot water demand. You may need a boiler with a higher output and/or a hot water cylinder.

  • Your boiler has a low energy efficiency rating (not A-rated) and is costing you a lot of money to run.

  • You are planning to sell or rent out your property. An A-rated boiler should improve the energy rating of your home which can make it more attractive to potential buyers or tenants.

  • Older boilers can pose a danger if there’s a risk of a gas leak or exposure to carbon monoxide poisoning. It’s important to note that even new boilers require maintenance and annual servicing by a Gas Safe engineer to ensure they are working effectively, efficiently and safely.

Having a new boiler installed will solve all of the above and offer a number of other benefits too, including:

  • Cheaper heating bills: While older boilers often only reach 50-70% efficiency, new A-rated models have to be at least 92% efficient by law. The less energy efficient your boiler is, the more fuel will be wasted and the higher your heating bills will be. Replacing a G rated boiler with an A rated boiler could save households up to £350 per annum.

  • Save money on repairs: As boilers age, they become more prone to faults and even complete breakdowns. The cost of having these issues repaired can really begin to add up, especially if your boiler is running into issues on a regular basis. A new replacement boiler will be much more reliable and, in the unlikely event that there is an issue, you’ll be covered by a manufacturer warranty.

  • Makes your home more comfortable: Replacing an old inefficient boiler with a newer model should improve the comfort of your home as it will heat your home more effectively. This is particularly important if there are vulnerable people in the home such as young children or elderly people.

  • Better for the environment: A new A-rated boiler which wastes less fuel will help to bring down your household’s carbon emissions and reduce your impact on the environment.

  • Add value to the property: Your home will be more energy efficient and therefore more attractive to potential purchasers when you come to sell it.

  • More control over the central heating: Modern boilers can be paired with smart thermostat technology, giving you greater control over your central heating.

  • Quieter during operation: The last thing you want is for your boiler to disturb you as it works to heat your home. And modern boilers are designed with quiet operation in mind. Look out for Quiet Mark Accreditation when comparing new boilers.

  • Save some space in your home: As boiler technology has advanced, boilers have shrunk in size. So if your existing boiler is a number of years old then a replacement boiler could take up much less space and even be hidden away in a kitchen cupboard.

How much does a boiler replacement cost?

Boiler replacement costs will vary depending on the work involved.

Below is the potential cost of a gas boiler replacement in a home with 3 bedrooms. All of the figures in the table are averages and could go up or down depending on a number of factors. Firstly, there’s the type of boiler being installed. Gas boiler prices can range from as little as £400 to right up in the region of £3,000 depending on the manufacturer and model.

Secondly, when weighing up the potential cost of a boiler replacement, you will also need to consider the installation itself. As the price of boilers can vary so can the rates charged by heating engineers for the installation. Factors that will have an impact on how much the installation will cost include:

  • Type of boiler being installed (a like-for-like replacement will cost less than a complete change of heating system)
  • Whether the boiler is moving to a new location
  • The rates charged by the installer (installers in London tend to be more expensive than those in other areas of the UK)
Boiler type Average cost of boiler excluding installation Average labour cost of boiler installation Approximate total cost of boiler fully installed
Combi £500 – £2,000 £500 – £1,000 £1,000 – £3,000
System £500 – £2,500 £500 – £1,000 £1,000 – £3,500
Conventional £500 – £2,750 £500 – £1,000 £1,000 – £3,750

As there are so many variables that can have an impact on boiler replacement costs, all of the costs in the table are estimates. To get a more precise idea of boiler replacement costs, we highly recommend getting quotes from multiple Gas Safe registered engineers.

Find out more about what’s involved in boiler installation.

How to choose a new boiler

Choosing a new boiler involves a bit of research as you’ll need to know the type of fuel your boiler runs on, which boiler type will suit your home and the most suitable boiler size (output rating) for your heating and hot water demands.

Finding out which fuel your boiler uses

When arranging a boiler replacement, it’s vital to know which fuel your current boiler uses: gas, oil, electricity or liquefied petroleum gas (LPG).

The most common fuel used for boilers in the UK, by far, is natural gas. If your home is connected to the gas network then it’s likely that you have a gas boiler. You will have a gas meter outside your property and will make regular payments to an energy supplier. Find out

Not all properties are connected to the gas network, meaning that a gas boiler can’t be installed. In this case, the alternatives run on oil or LPG, both of which have to be stored onsite. Rather than having the fuel delivered directly to your property through an extensive pipe network, oil and LPG will be delivered and stored in a tank outside your property.

An electric boiler doesn’t look too dissimilar to gas and oil boilers but there are some key differences. As electric boilers operate they don’t burn fuel, unlike gas and oil units. This means that electric boilers don’t need a flue – a pipe which expels waste gases away from the property – making them easily identifiable.

If you’re unsure which fuel your boiler runs on, then you will be able to find out in the paperwork that came with your boiler. Alternatively, a fully-qualified heating engineer will be able to let you know.

Choosing a boiler type for your home

When it comes to deciding on the right boiler type for your home, there are 3 to choose between:

  • Combi
  • System
  • Conventional

The size of your property and the level of demand for central heating and hot water, all play a part in which boiler type would be the most suitable choice. Each boiler type has its own pros and cons so it’s a case of weighing these up, with the help of a heating engineer, before making a decision.

Combi boilers
A combi boiler heats water from the mains and circulates it directly to either the central heating system or hot water outlet on demand, as and when needed. This is opposed to heating water to be stored in a cylinder where it sits until needed. And depending on the size of your property, this could either be a pro or a con. For smaller properties, with 1-2 bathrooms, this is perfect as the heating system won’t take up any additional space (for cylinders or tanks) but it comes at a cost for larger properties as they can’t meet higher demands for heating and hot water.

Thanks to being cost-effective compact units, the popularity of combi boilers has risen sharply in recent years and are now the most popular boiler type in the UK.

Read our comparison to find out Which is the Best Combi Boiler.

System boilers
With a system boiler, you’re getting a heating system that sits somewhere in between combi boilers and conventional boilers. They heat water directly from the mains, like a combi, but rather than delivering it to the tap instantly, it is stored in a hot water cylinder. This removes the need for any tanks in the loft and means that they can deliver hot water to multiple taps or showers at the same time with a stronger pressure than a combi.

Want to know more about system boilers? Then read through System Boilers Explained.

Conventional boilers
Conventional boilers go by many names, including regular, heat-only and open-vent. They’re the oldest type of heating system around and are most commonly found in older properties. While conventional boilers pre-date both combi and system boilers, they have evolved significantly over the years.

Conventional boilers get their water supply from a cold water storage tank, situated in the loft. Alongside the cold water tank is a feed and expansion tank which ensures that the correct level of water is in the heating system at all times. This is important as water expands when heated.

To heat up the central heating system, cold water is delivered to the boiler via gravity where it is heated and then circulated to the radiators. For domestic hot water, cold water travels down to a hot water cylinder where it is then heated up and stored until needed.

As you can see, conventional boilers are made up of several parts, which means that plenty of room is needed within the property to house them all. And due to this, conventional boilers are recommended for properties which already have the appropriate pipework in place.

To learn more about conventional boilers, our guide to What is a Regular Boiler? includes everything you need to know.

Choosing a boiler size

Boiler size is better known as the output rating and it’s one of the most important things to consider when researching a replacement boiler. Output rating is measured in kilowatts (kW) and the higher the output rating, the more powerful the boiler.

When it comes to output rating, more powerful doesn’t necessarily mean better. It’s important to get a new boiler with an output rating that’s suitable for the heating and hot water demands of your home.

“An output rating that’s too low won’t be able to meet the demand while you could see your heating bills rise if the output rating is too high.”

Domestic boilers typically have output ratings of between 24 kW and 42 kW and you can use the number of radiators and bathrooms in your home to find a new boiler with a suitable output rating.

Number of bedrooms Number of radiators Bathrooms Output rating Boiler type
1-2 10 1 24 – 27 kW Combi
3 15 2-3 28 – 34 kW System
4 20 3 35 – 42 kW System or conventional

It’s essential that you get the right boiler size to suit the heating and hot water demands of your home so find out more in What Size Boiler Do I Need?

Choosing a boiler brand

With so many boiler manufacturers out there, it can be hard to know where to start. It’s important to do your research as the boilers manufactured by a certain manufacturer could be better suited to your home than another. So, when comparing manufacturers, you should consider the following:

Customer reviews
You can find out how reliable a manufacturer’s boilers are by getting the opinion of existing customers. Sites such as Trustpilot include honest customer reviews of brands as a whole while our Boiler Comparison Tool includes customer reviews and ratings of specific boiler models.

Heating engineer recommendations
Heating engineers are industry experts so if you’re looking for an opinion you can trust, there’s no better person to ask. It’s worth noting that some heating engineers will have an association with certain manufacturers.

All boilers come with a warranty to see that you’re covered in the unlikely event of an issue after the installation. The length of the warranty can help to give you an idea of how reliable a certain manufacturer’s boilers. All boilers come with a warranty of at least 1 year and can be as long as 12 years in some cases. Ariston, ATAG, Baxi, Ideal, Vaillant and Worcester Bosch all offer lengthy warranties of between 10 and 12 years on some of their boiler models.

While warranty length is important, you should look into what it covers too. Some will cover parts and labour while others might only cover the labour.

To keep your warranty valid for its full length, you will need to abide by the manufacturer’s terms and conditions. These will vary from manufacturer to manufacturer but one constant is to have your boiler serviced annually by a Gas Safe registered engineer.


Which are the best boilers?

When it comes to comparing the best boilers, you’ll find that there are a number of boiler manufacturers. And each of these manufacturers offer several ranges.

By asking ‘which are the best boilers’, there is no same answer for every installation. This is because different properties have varying levels of demand for central heating and domestic hot water. To find the best boiler for your home, you will need to consider the most suitable boiler type, output rating and whether it’s within your budget.

A list of the best boilers wouldn’t be complete without including the leading boiler brands Worcester Bosch, Vaillant, Baxi and Ideal. Each of these boiler manufacturers can make a case for manufacturing the best boilers and we’re going to look at the most popular range manufactured by each of them.

“The best boilers are manufactured by Worcester Bosch, Vaillant, Baxi, Ideal and Viessmann.”


Worcester Bosch Greenstar i

Greenstar is the flagship range of boilers manufactured by Worcester Bosch. They’ve been designed to meet the heating and hot water demands of small to medium sized homes with combi, system and regular boilers available.

  • Available in a range of central heating outputs from 9.2 kW right up to 30 kW
  • Achieve an ErP A+ rating when installed alongside the Bosh EasyControl
  • Fitted with a low energy pump to reduce electricity consumption
  • Warranty period of up to 7 years

Vaillant ecoTEC Plus

Highly efficient performance is one of the major benefits of Vaillant ecoTEC Plus boilers. With a range of output ratings available across all boiler types, there’s a suitable model for a number of property types.

  • ecoTEC Plus combi boilers deliver hot water within 5 seconds
  • Precision heating technology can help to lower your heating bills
  • Fitted with a stainless steel heat exchanger for increased efficiency and reliability
  • Warranty of 5-10 years

Baxi 800

Baxi have built on their 600 range to deliver even more reliability and increased performance with their range of 800 combi and system boilers.

  • Compact design allows for installation within a kitchen cupboard
  • Fitted with an Adey Micro2 magnetic system filter to protect the central heating system
  • Available with a 10 year warranty

Ideal Vogue Max

Ideal has built up a great reputation as a leading boiler manufacturer and has a number of ranges that have proved popular over the years. As well as their Vogue Max boilers, the Logic Max range will include a suitable model for a variety of property types.

  • Designed with low lift weight for a quick installation
  • Boiler frost protection keeps units installed in lofts and garages running through the winter
  • Lengthy warranty of 10-12 years

Viessmann 200-W

Viessmann 200-W combi and system boilers have been designed to achieve high levels of efficiency and reliability in a user-friendly way.

  • Achieve highly efficient performance of up to 98%
  • A low fan speed keeps operational noise to an absolute minimum
  • The 1:17 modulation range keeps energy usage as low as possible to help reduce your bills

Let’s take a deeper look at the different models available in each range and how much you might expect to pay.

Boiler Brand Best Selling Boiler Range Combi Models System Models Conventional Models Price range
Worcester Bosch

Greenstar i

25i, 30i

9i, 12i, 15i, 18i, 21i, 24i, 27i, 30i

9Ri, 12Ri, 15Ri, 18Ri, 21Ri, 24Ri, 27Ri, 30Ri

£800 – £1,100

ecoTEC Plus

825, 832, 835, 838

612, 615, 618, 624, 630, 637

412, 415, 418, 424, 430, 435

£825 – £1,550


825, 830, 836

818, 824


£800 – £1,100

Vogue Max

C26, C32, C40

S15, S18, S26, S32


£1,000 – £1,300


25/30, 32/35

11, 19, 25, 30


£1,350 – £1,700

What happens during a new boiler replacement?

Before boiler replacement day arrives, it’s important to not only find the most suitable boiler but a competent heating engineer to carry out the installation too. And the best way to do this is by comparing multiple quotes.

If you were to receive and accept a boiler installation quote from a single engineer, then you wouldn’t know if you were getting the most competitive price. Getting quotes from at least 3 different companies is the best way of knowing that you’re being quoted the most competitive price by the most competent installer.

At Boiler Guide, we’ve made the whole process of finding multiple heating engineers in your area a lot more straightforward. By tapping through our online form, letting us know some details about the work, you can get free quotes from up to 3 heating engineers based in your local area. You’ll then be in a position to compare multiple quotes and go ahead with the boiler replacement confident that you’ve hired the best installer for the job.

So, what happens on the day of the boiler replacement? Well, this will vary depending on the work involved.

A like-for-like boiler replacement (replacing your old combi with a new combi) is the most straightforward and can be completed within a single day. While a complete system change, such as having a conventional boiler replaced by a system boiler, will require a change to the pipework, removal of the tanks in the loft and the installation of a new hot water cylinder. As a result, a complete change of system is a much more complex job and could potentially take 2-3 days.

“A like-for-like boiler swap is the most straightforward and budget-friendly boiler replacement.”

A boiler replacement can also be made more complex if you’re planning to move the boiler to a new location. More often than not, a boiler is installed in the kitchen or a utility room, however, these aren’t your only options. The main incentive for moving a boiler is to free up space in a particular room and common alternatives to the kitchen or utility room include a garage, loft or even a bedroom. Moving the location of your boiler will require new pipework and, in the case that it’s a gas boiler being moved further away from the gas meter, a bigger gas pipe too.

Once your new boiler has been installed, the heating engineer should take you through how to use the heating controls. Your engineer should leave you with a Building Regulations Compliance certificate confirming the boiler was installed safely.

You can help to make the engineer’s job a lot easier by clearing the space around the boiler ahead of their arrival. This will help to save them time on the day of installation so that your boiler can be replaced as quickly as possible.

Getting the best deal on a new boiler

If your need for a replacement boiler has come out of the blue then the costs can be hard to stomach. Rather than going for the cheapest boiler on the market, which is unlikely to last as long, you might want to consider paying for your boiler in installments through boiler finance or a pay monthly arrangement.

Boiler finance
Boiler finance will allow you to spread the cost of a boiler replacement over a period of time. And while some boiler finance deals are interest free, the interest rates can soar in some cases so it’s important to read the terms and conditions closely.

Boiler finance deals are offered by some boiler manufacturers, energy suppliers and heating engineers. As part of the application process, your credit rating will be checked to ensure you’ll be able to keep up the payments. Once approved, the lender will cover the new boiler costs and you will pay them back in line with your pre-agreed arrangement.

“Boiler finance deals allow you to spread the cost of your new boiler out over a period of time.”

Compare quotes
Before thinking about payment plans, you need to know how much you should be expecting to pay. And to do this, you will need to get a boiler installation quote from a Gas Safe registered engineer. However, getting just one quote won’t ensure that you’re getting the most competitive price. And that’s why we recommend getting quotes from at least 3 different heating companies.

At Boiler Guide, our aim is to get you the most competitive price on your new boiler installation. To do that, we’ll match you with up to 3 local heating engineers. All you have to do to get your free quotes is take a few moments to complete our simple online form. We’ll use the information you provide to match you with local heating engineers who are fully qualified to carry out your boiler replacement.