Gas Boiler Costs 2020

gas boiler

By 12 min read


A gas boiler can cost anywhere from around £500 to more than £3,000

You can save more than £300 a year on your energy bills with a new A-rated gas boiler

To get a bespoke quote for an efficient boiler, fill in the form above


Looking for a new way to save energy and a few extra pennies each month? Fed up of your old boiler taking ages to get your home nice and cosy? Or just looking for a new boiler for the future? Gas boilers are the answers to all of these questions — they are both energy and cost efficient, effective, and only show signs of improving in the future.

Before we dig into the nitty gritty of gas boilers, if you’d like to receive free quotes from local professionals, head over to our details page, to enter your details. Once you’ve completed this our suppliers will be in touch with quotes for you to compare.

In This Gas Boiler Guide:


How Much Does a Gas Boiler Cost?

Gas boiler prices start at around £500 and go up to more than £3,000. This table gives you the price range of gas boilers from the most popular boiler manufacturers:

Gas Boiler Manufacturer
Gas Boiler Cost
Alpha
£700 to £2,250
Baxi
£570 to £2,172
Glow-worm
£640 to £1,520
Ideal
£590 to £2,200
Intergas
£650 to £1,100
Potterton
£610 to £1,000
Vaillant
£740 to £1,500
Viessmann
£740 to £1,500
Vokera
£575 to £1,200
Worcester Bosch
£570 to £6,188

The price of a new gas boiler is affected by factors including the make, model and quality of the boiler, the size of the boiler and the warranty. While more powerful gas boilers will generally cost more than smaller boilers, you can see from the prices we’ve found that it isn’t a straightforward correlation; the price also depends a lot on the manufacturer.

Did You Know?

In terms of efficiency, there is not much to choose between new gas boilers these days. A new law was brought in in April 2018 requiring all new gas condensing boilers to be at least 92% efficient

You can buy a gas boiler yourself of course, but to get an accurate price for installation, you’ll need a heating engineer to visit your home to see how much work needs to be done.

However, a good engineer is also an invaluable source of advice on the best types, brands and size of gas boiler for your household, and what your options are in terms of where you can install it and what improvements you could make to your heating system as a whole.

Could You Save With a New Gas Boiler?

Select How Many People Live in Your Home to Find Out!

Boiler House

 


Combi Gas Boiler Cost

You can expect to pay between £500 and £2,000 (though normally less than £1,500) for a gas combi boiler. The tables below show you cheapest and most expensive gas combi boilers depending on their size (in kW).

Size
Price Range
Cheapest Model
Most Expensive Model
Up to 24kW
£527 to £1,221
Vokera Compact 25a
Baxi Platinum 28
24kW to 29kW
£528 to £1,989
Ideal i-Mini 24kW
Worcester Greenstar Highflow 440CDi
30kW to 35kW
£577 to £2,447
Ideal i-Mini 30kW
Worcester Greenstar Highflow 550CDi
35kW to 40kW
£1,152 to £1,260
Glow-worm Energy 35C
Ideal Vogue C40 Gen2

 


Conventional Gas Boiler Cost

A conventional (or regular or ‘heat only’) gas boiler will cost anywhere between £700 and £2,020, depending on its size and the brand. Here you can get a sense of the cheapest and most expensive models on the market.

Size
Price Range
Cheapest Model
Most Expensive Model
Up to 24kW
£701 to £949
Ideal Logic Heat Only 12
Baxi EcoBlue 24
24kW to 29kW
£801 to £988
Ideal Logic Plus 24 HE
Baxi EcoBlue Advance 25 Heat
30kW to 35kW
£880 to £1,476
Glow-worm Energy 30R
Worcester Greenstar FS 30CDi
35kW to 40kW
£1,500 to £2,019
Vaillant ecoFIT pure 435
Worcester Greenstar FS 42CDi

 


System Gas Boiler Cost

A gas system boiler will set you back anywhere between £630 and £1,420. We’ve listed the most affordable and most costly system boilers below.

Size
Price Range
Cheapest Model
Most Expensive Model
Up to 24kW
£658 to £1,115
Vokera Vision 20S
Ideal Vogue S18 System Gen2
24kW to 29kW
£634 to £1,168
Vokera Vision 25S
Vaillant ecoTEC Plus 624
30kW to 35kW
£888 to £1,252
Ideal Logic Plus 30
Vaillant ecoTEC Plus 630
35kW to 40kW
£835 to £1,416
Vokera Mynute 35 HE
Vaillant ecoTEC Plus 637

 


Think of the Money You’ll Save on Your Bills!

How much you save with a new boiler will depend on how much heating and hot water your household uses and how inefficient your old boiler is. The Energy Saving Trust estimates that swapping a creaking old G-rated boiler for a new A-rated boiler could save you more than £300 a year if you’re in a detached house. And that’s without factoring in the cost of repairs, which boilers are increasingly likely to need as they get older.

Type of Property
Gas Boiler Cost and Installation
Annual Energy Bill Savings
Time Needed to Break-Even
Return on Investment After 10 Years
Detached House
£3,020
£570
5.2 years
£2,680
Semi-Detached House
£2,632
£350
7.7 years
£768
Bungalow
£2,320
£290
8.0 years
£580
Mid-Terrace House
£2,320
£280
8.3 years
£480
Mid-Floor Flat
£2,112
£145
14.6 years
-£967

*These figures are based on replacing a G-rated condensing gas boiler with a new A-rated condensing gas boiler

 


Gas Boiler Installation Cost

Like-for-Like Installation

Replacing a condensing gas combi boiler in the same position as the previous one is likely to cost from £540 to £660, which includes the removal of your old boiler. And replacing a non-condensing boiler with a condensing one in the same position will set you back between £640 and £770.

New Boiler in a New Position

If you’re having a new gas boiler installed in a different place, you’re looking at anywhere between £1,140 to £1,440; this is because the work is much more complex and will involve things like new pipework. It’s a similar story when it comes to replacing a conventional boiler with a combi boiler, for example, and you should ideally budget for around £1,440.

Installation costs will depend not only on the make, model and size of the boiler, but also on how much work needs doing to fit it. Boiler installations aren’t always straightforward. Additional work such as adding or removing pipes, performing a chemical flush of your central heating system, or updating the flue will drive up the cost of your gas boiler installation.

Here is the typical cost of some common installation work:

Boiler Installation Extras
Typical Cost
Chemical flush
£200 to £500
Adding a filter
£120
Moving pipes
£200 to £300
Powerflushing 10 radiators
£300
New radiators
£70 to £150 per radiator
New wireless programmer and thermostat
£180
Thermostatic radiator valves
£20 per radiator
New 120 litre hot water cylinder
£250 to £300
Upgrading the flue
£250 to £400

Getting your boiler installed properly is important to make sure it lasts as long as possible. Things like filters and chemical cleans can increase its lifetime and may be required under the warranty.

 


What Type of Gas Boiler Do You Need?

The first thing you need to think about when you decide to buy a new gas boiler is what kind you want. There are 3 main types – all of them will heat both your radiators and your hot water, they just differ in how they work.

  1. Combi boilers (or combination boilers) are now the most popular choice in the UK. They provide instant, unlimited hot water and heating with no need for a water tank or cylinder, which saves space. However, because the water comes straight from the mains, the flow and pressure may be reduced if you need hot water from more than one tap at a time, so they aren’t always the best option for larger homes. Read more on our combi boilers page.
  2. Conventional boilers (or regular or ‘heat only’ boilers) have tanks in the loft and a hot water cylinder, so they take up more space than a combi boiler and you can’t just turn on a tap and have hot water – you have to heat it up. But you can use several taps at the same time without a loss of pressure – and if the cylinder has an electric immersion heater, you can still have hot water if your boiler breaks down. Read more on our conventional boilers page.
  3. System boilers are kind of a halfway house, with a water cylinder but no tank. They share many of the advantages and disadvantages of a conventional boiler, but the absence of a tank means they take up less space. This setup also avoids the risk of the tanks freezing in the loft and leaking. Read more on our system boilers page.

Another term you might hear is condensing boiler. Condensing boilers reuse some of the heat which the boiler would otherwise lose, so they are very efficient. All new gas boilers have had to be condensing since 2005, other than in a few homes where it would be impractical to install one.

Did You Know?

Gas has traditionally been the most popular fuel in the UK – it’s one of the cheapest fossil fuels, as well as one of the least harmful in terms of carbon emissions.


What Size Gas Boiler Do You Need?

A boiler’s size is measured in kilowatts. The bigger the boiler, the more heating and hot water it will be able to provide.

How big a boiler you need will depend on the size of your home, how many radiators, bathrooms and hot taps it has, how many people live there and how much you usually use your heating and hot water. These are generally accepted to be the boiler sizes you will need for different sized homes:

Number of Bedrooms
Number of Bathrooms
Number of Radiators
Boiler Size
1 or 2
1
Up to 10
24kW to 27kW
3 or 4
1 or 2
Up to 15
28kW to 34kW
4 or more
2 or more
More than 15
35kW to 42kW

 


Who Should Install Your Gas Boiler?

You should always use a Gas Safe registered engineer to install your gas boiler. Otherwise, they’re not qualified to do the job and are working illegally. Unsafe gas work can cause leaks, explosions and fires and put you at risk of carbon monoxide poisoning.

You can check that an engineer is Gas Safe registered on the Gas Safe Register website or by calling 0800 408 5500. Your engineer should also have a photocard to say they are Gas Safe registered. The card should say what kind of work they are qualified to do, so make sure it says gas boiler and pipe work on the back and that these qualifications are in date too.

It’s also illegal for someone who works for a Gas Safe registered business to do private work. You must hire them through the firm.

Did You Know?

A report from the Committee on Climate Change (CCC) announced in 2019 that, as of 2025, gas boilers will be banned from newly built houses.

 


FAQs

Can you get a new gas boiler on finance?

Yes you can. If you’re unable to pay for your new gas boiler upfront, most companies allow you to pay for your boiler in small monthly payments, typically over one to five years. Interest is often added to the amount you pay back, however, so you’ll end up paying more for your gas boiler than it’s actually worth.

How much can you save with a new gas boiler?

You can save hundreds of pounds on your energy bills by updating from an old G-rated gas boiler to a new A-rated gas boiler. For example, a semi-detached house can save up to £350 every year, while a detached house can save up to £570 a year. Most households will break-even on their new gas boiler within 8 years.

Who makes the best gas boilers?

Ideal, Vaillant, Viessmann and Worcester Bosch make the best gas boilers. These brands have been recommended by both homeowners and boiler engineers for their build quality, reliability and performance.

Can a plumber install a gas boiler?

No. A plumber can carry out ‘wet work’, such as installing new water pipes and radiators, but they are not allowed to install the boiler itself. A Gas Safe registered engineer is the only person allowed to install a gas boiler and connect it to the pipework and radiators.


What next?

Like what you’ve seen from our trusty gas boilers? Before you commit to a boiler, it’s best to compare different types, brands, and sizes of boilers that you think will be suitable for your home.

One way of doing this is by heading over to our short details form, and pop in your information. Once you’ve done this, our local professional installers will get in touch with free boiler quotes to compare.

Fran Whittaker-Wood Editor

Fran is The Eco Experts’ resident solar panel and double glazing oracle She loves orangutans and is passionate about protecting the planet’s rainforests from the unsustainable production of palm oil. And minstrels.