How Much Does a New Boiler Cost [2023] Re February 3, 2023

How Much Does a New Boiler Cost [2023]

Woman choosing a boiler

How much does a new boiler cost?

Buying a boiler can be an expensive business, so we’ve created the ultimate new boiler cost guide to navigate you through the perilous seas of boiler buying, charting your way around some of the more common pirates out there looking to rob your gold.

It’s a common misconception that you need to buy your boiler from whoever your energy supplier is. You don’t. But if you do, you’ll likely pay way over the odds for the pleasure and have to wait around weeks before you even get to speak to a sharky salesman, let alone have your boiler fitted.

Another common issue that confuses people about the cost of a new boiler is whether the price includes installation or not. Don’t get suckered in by low lead prices at wholesalers, yes, you can buy a new boiler for £699, but if it costs another £1,000 to get your boiler fitted then you may have got a better package all-in.

All WarmZilla boiler prices include Gas-Safe installation as standard. It also includes a system filter, system cleanse, guarantee, smart thermostat, and any other bits and bobs you need to get your boiler up and running. Not all prices include boiler installation, make sure your quote does as you’ll be looking at £500 – £1000 to get a boiler installed.

There are a lot of factors that contribute to what price you will pay to get a new boiler installed but this guide will explain all of the factors and give you example prices so you’ll know exactly how much you can expect to pay.

Alternatively, you can save yourself time and find a new boiler the WarmZilla way – where your price is fixed, everything is included and our online survey will work out exactly what boiler you need based on your answers to some simple questions.

Do I need a new boiler or should I repair my current one?

The first question to ask when considering whether or not to buy a new boiler is whether you actually need to replace your old boiler or whether you can get it repaired and get some more use out of it.

The answer usually comes down to how old your current boiler is. Modern combi boilers have a lifespan of between 10-15 years depending on the brand and whether it’s had an annual service or not.

According to a study done by the BEIS (Department for Business, Energy & Industrial Strategy), 66% of UK homeowners would only replace their current boiler if the system failed or showed strong signs of deterioration.

If you have a back boiler and you’re thinking of replacing it, you should. They are incredibly inefficient and you will see instant savings on your heating bill of around £300 per year. We’ve written a guide with everything you need to know about replacing a back boiler.

Reasons to replace your old boiler include:

  • Repair costs – Repair costs on a boiler are not cheap and can quickly become a false economy, we’ve spoken to many customers who repaired their old boiler more than once and wished they had just cut their losses at the first repair bill.

If your boiler is over 8 years old and has had more than one repair then the chances are that the numbers of repairs are only going to increase. Rather than getting it fixed at £200 a go, you could put that towards a new boiler from WarmZilla – starting from £1489 inc. VAT.

  • Inefficiency – Older boilers are less energy-efficient, meaning your energy bills will be higher. Modern condensing boilers are 90% and above energy-efficient. Back boilers are around 78% energy-efficient. Switching from an inefficient boiler to a modern boiler can save up to £300 per year on your heating bill.

  • Better for the environment – As well as saving you money, a higher-efficiency boiler is also better for the environment and produces fewer carbon emissions.
  • Increased kW output – If your current boiler doesn’t service your heating and/or hot water needs sufficiently then you may want to buy a new boiler with a higher kW output that can.
  • Safety – Older boilers have a higher chance of a gas leak and carbon monoxide poisoning. Modern boilers have more safety features and use superior technology to what was used 10-20 years ago.
  • Increase property value – Surprisingly, the best investment to increase property value is to replace the boiler. Adding up to £8,000 to your property value with a spend of only £1,500 – £2,500, it’s the best value for money home improvement out there.

If you own a rental property a new boiler also increases the rentability by offering lower energy bills for tenants.

Do I need a system, regular or combi boiler?

The next question to help determine how much a new boiler is going to cost, is what type of boiler do you need. If you aren’t sure what type of boiler you have then we have covered that in a previous article, but here is a quick overview:

  • Combi Boiler

The most popular boiler type in the UK. You can identify a combi boiler as it is not connected to a hot water storage tank (airing cupboard) or a cold water storage tank (usually found in the attic or loft).

A combi boiler works by heating water directly from the mains supply, this means that you don’t waste energy by heating water that you may or may not use.

  • System Boiler

A system boiler has a hot water storage tank but doesn’t have a cold water storage tank. They are usually found in older houses or houses with more than one bathroom as they can supply hot water simultaneously to multiple bathrooms as it’s stored in the hot water tank.

  • Regular Boiler

Regular boilers have both a hot water cylinder (usually in the airing cupboard) and a cold water storage tank in the attic/loft. Like system boilers, they can cater for multiple bathrooms using hot water simultaneously but they do take up a lot of storage space with tanks. Standard boilers are sometimes referred to as traditional, standard, open vent, or heat only boilers.

  • Back Boiler (BBU)

Back boiler units are located behind an electric gas fire. As is the case with a regular boiler they will usually have a hot water storage tank and a cold water storage tank.

Back boilers are becoming less and less common as they are less efficient than modern combi boilers and they are no longer installed.


Boiler typeBoiler (without installation)Installation (without boiler)Total (boiler + installation)
Combi   £500 – £2,000£500 – £1,000 £1,000 – £3,000
System £500 – £2,500 £500 – £1,000 £1,000 – £3,500
Regular£500 – £2,500 £500 – £1,000 £1,000 – £3,750

What kW size boiler will I need?

When people talk about how powerful your boiler needs to be they are referring to the kW (kilowatt) output. The higher the kW output of a boiler, the more it can cope with your heating and hot water demands.

You will need to choose a boiler that can cope with the heating demands of your home. This depends on the size of your home, how many radiators, and how many baths there are. Below is a very rough guide on the kW boiler that will cater to your home. If you want to learn more about boiler kW output then check out our previous article.

24 – 27 kW Combi
Suitable for most flats, apartments, and smaller houses with up to 10 radiators and 1 bathroom.

28 – 34 kW Combi
Suitable for 3-4 bed houses with up to 15 radiators and 2 bathrooms.

35+ kW Combi
Suitable for large houses with up to 20 radiators and 3 bathrooms.

This is not something you will need to worry about when getting a boiler quote from Warmzilla as we will automatically suggest the right kW boiler based on the answers you give to survey questions.

The higher the kW boiler the more expensive it would be (on a like-for-like model).

How much does it cost to move my boiler?

Moving your boiler can cost anywhere between £300 – £800 depending on how far it’s being moved, what type of boiler it is and where it’s being moved to.

It’s not as simple as remounting the boiler elsewhere, the pipework leading to the boiler needs to be rerouted and reconnected, which can mean pulling up floorboards etc.

Costs could increase if additional parts are needed for the new location, for example, if you move the boiler from a location where the flue terminates horizontally from the boiler through a kitchen wall, to an attic where the flue will need to be changed to a vertical flue, additional costs for parts will be incurred.

Generally speaking, the further you move your boiler from its current location the higher the cost. This is due to the labour of running the new pipework and the cost of the materials required.

It may become a more viable option if you’re thinking about moving an older boiler to consider buying a new one instead and get it installed in your preferred position.

If your new boiler location is in the same room or fairly close to the old location then it should take between half a day to a day to move. If you’re moving a boiler from the kitchen to the loft then expect it to take a minimum of one day and more probably two days.

At WarmZilla we charge £150 to move your boiler within the same room, £300 for other rooms and £500 to move your boiler into the loft.


What if I need to upgrade my pipework?

Most people wouldn’t hear about this until their installer was informing them that they were going to need to pay an extra fee to upgrade their pipework. Not with WarmZilla. The price we quote you is fixed. If we need to upgrade the pipework then it won’t cost you any more.

Older heating systems used different size piping (usually 15mm), modern regulations require gas piping to be 22mm. Upgrading pipework would usually cost you between £300 – £500.

We will identify whether your pipework needs to be upgraded prior to installation in most cases.

How much does a powerflush cost?

A powerflush is kind of what it sounds like – a powerful flushing out of your system. The idea is to flush out the ‘sludge’ by attacking it with very high-pressure water flow together with a powerful system cleaning agent.

Sludge is a build-up of rust and dissimilar metals in your heating system that wants nothing more than to make you cold by stopping your radiators from getting hot and then eventually moving in for the kill on your boiler.

If your system seems to be performing well (your house is nice and warm & there are no cold patches on your radiator), then you probably don’t need a powerflush. In most cases, the standard chemical flush is enough to give the system a cleanse before installing a new boiler.

Powerflushing can also cause leaks in older systems as the flushing process is quite vigorous, so avoid unless you need one.

Depending on which company you use and how many radiators are present in your property, a powerflush can cost between £300-£600. See our table below for a rough guide on costs. 

Number of radiatorsEstimated cost of power flush

Do I need a system filter?

A system filter/magnetic filter is a metal/plastic component that is connected to the return pipework of a central heating system. Inside, it has a very powerful magnet that grabs any sludge that builds up in the system over time before it reaches your boiler.

Supply and fit of a magnetic filter will cost you anywhere between £120 – £250 depending on brand and installer. Again, with WarmZilla, there is no charge, we include a system filter as standard with every boiler we install.

Is the price of a flue included?

The flue is connected to your boiler and its job is to remove harmful gases and condensation produced by your boiler outside your property.

With WarmZilla the price of your flue is included in the quoted price. Based on your answer to the flue question in the WarmZilla survey you will either require a vertical or a horizontal flue.

Horizontal flues are easier to install and therefore cheaper, unfortunately, the opposite is true for vertical flues as it’s more difficult to install a flue leading through a roof.

Your boiler is legally required to have a flue so the cost will always be incorporated into the final price and if it’s not, then you have a rogue trader on your hands and you should have chosen WarmZilla!


Do I need a plume kit?

A plume kit is basically an extender for your flue and is used in cases where the flue is too close to a door/window or your neighbours home and people are at risk of being exposed to the gases released from the flue.

As ever, the cost of the plume kit is included in your WarmZilla fixed price boiler quote. It will automatically be included in your order if the answers to the survey indicate that it’s necessary.

A plume kit will usually cost between £100 – £150.

Is installation included in the cost?

Gas Safe installation is included in your fixed price boiler quote from WarmZilla.

In many cases the installation cost is higher than the cost of the boiler itself, so be very wary of buying a boiler for £600 on its own and thinking it’s a bargain. Once you add boiler installation, system filter, flue/plume kit, smart thermostat, and a system cleanse into the final price you’ll find it’s a false economy.

Installation costs vary by company, location, and the boiler type that’s being installed. A combi/combi swap (4 – 8 hours) will be far less labour than a back boiler conversion (1.5 – 2 days) and this will be reflected in the price.

It’s also worth bearing in mind that some national energy companies have much higher overheads to cover than a nifty little whippet of an online company like WarmZilla. Our lower overheads are passed on to the customer, with unbeatable prices.

How much does a smart thermostat cost?

There is a wide range of smart thermostats all with different functions and with different price tags. We’ve already reviewed some of the most popular wireless/smart thermostats on the market including the Hive Smart ThermostatGoogle Nest Learning Thermostat, and the Salus RT310i.

A smart thermostat is often confused with a wireless thermostat. A thermostat that you can control with your phone is not necessarily a smart thermostat. For it to be ‘smart’ there has to be another level of sophistication, such as learning your home habits and adjusting the heating accordingly.

For example, the Nest Learning Thermostat learns what times you are home, what rooms you occupy, and what temperature you like to be. Later-generation Nest’s can even recognise how far away from the display you are and adjust the screen display in accordance.

Smart thermostats are getting smarter all the time with added functionality – such as energy usage reports, room sensors, home automation (connecting with other smart home devices such as smart lights), touchscreens, and geofencing (your phone triggering the heating to turn off or on depending on the proximity from your router).

Smart thermostats make your home heating more efficient and help to save money on your heating bills. If you haven’t got one yet, we definitely recommend getting one. In addition to saving you money, they are also more convenient, allowing you to control your home temperature from your phone, Alexa, or tablet. No more walking to the wall thermostat (although there is still the option to with smart thermostats if you want the exercise).

Tado says that its smart thermostat ‘will pay for itself within a year’ by reducing your heating bills by up to 31%. Netatmo claims that its smart thermostat will reduce the energy you use by 37%.*

With every boiler installation, WarmZilla includes a Salus RT310i as standard, it’s not as advanced as a smart thermostat such as the Google Nest but you can upgrade to a Nest if the extra gadgetry is what you want in your life.

Heating controls vary from £100 – £350 at the top end (including installation).

What brand of boiler should I choose?

When choosing your new boiler it’s important to choose a trustworthy boiler brand. One way of identifying a trustworthy brand is what awards they’ve won. Worcester Bosch for example, has won the Which? Best Buy boiler for the last ten years. A sure sign that they are producing reliable boilers. It also shows that they have been around for a while, so if you have a ten-year guarantee, they will still be around in ten years’ time to honour it.

Everyone has their own opinion on which is the best boiler brand and it only takes one bad experience with a boiler to curse the brand for the rest of time. Having said that, boiler brands that are commonly regarded as good are Worcester Bosch, Viessmann, Vaillant, and Ideal.

We’ve already reviewed the best boiler brands in 2020, looking at both budget and premium boiler brands.

According to a Which? Survey, the average cost of a boiler repair is £210, so it’s worth going for a reliable boiler that will serve you well for the next 15 years. You may save a couple of hundred on the initial purchase price but that’s just one repair job in the future and you’re out of pocket.

According to Which?

“If you choose the most reliable brand of boiler, according to our survey, an impressive 63% are likely to still be fault free after six and a half years. Get unlucky and pick the least reliable brand, and this falls to a disappointing 45%”

WarmZilla currently offers Ideal and Worcester Bosch boilers as we feel they are reputable companies that have been around for a long time and they are both award-winning manufacturers for both the product and their customer service.

What payment options are there on a new boiler?

Paying for a new boiler is a lot more flexible than it has been in the past. No more handing over a briefcase of cash to a man that rocks up at your house in a white van, hoping that he does a good job.

  • Pay in full
    You can still pay for your boiler in full if you choose to but now there are a lot more options allowing you to spread the cost should you wish to do so. WarmZilla accepts payments via Stripe, for secure and reliable online payments.
  • 0% Finance
    Certain finance options allow you to pay 0% interest on the loan to buy your new boiler. These finance plans are usually over two years, allowing you to spread the cost to a more affordable amount without having to pay hefty interest fees for the pleasure.
  • Boiler Finance
    Many companies, heating engineers, and energy suppliers will offer boiler finance for varying lengths and terms from 1 – 10 years. Usually the longer you spread the payments the higher interest amount you’ll end up paying in the long run as the risk is greater to the lender.

We’ve covered boiler finance in-depth in a previous article.

WarmZilla offers a wide range of finance plans, with options of paying no deposit – useful if your boiler has broken down and you haven’t got any savings to cover it. Our finance providers, Vendigo, have a high acceptance rate, even for customers with less than ideal credit ratings.

We offer 0% finance on certain boilers and for the remaining boilers, the interest is 11.9% APR. Below are a couple of finance examples to give you an idea of what to expect with a boiler finance package.

11.9% APR – Worcester 12Ri Boiler:
Representative Example: Amount of Credit £825.00. Deposit £825.00. 120 Month Agreement. Total Purchase Price £1650. 120 Monthly Payments £10.68 p.m. Interest £456.04. Interest rate 11.9% p.a. Representative APR 11.9%. Total amount Repayable £2106.04. Example boiler: Worcester Bosch 12Ri.**

0% APR – Worcester 25Si Boiler:
Representative Example: Amount of Credit £1089.50. Deposit £1089.50. 24 Month Agreement. Total Purchase Price £2179. 24 Monthly Payments £45.40 p.m. Interest £0. Interest rate 0% p.a. Representative APR 0%. Total amount Repayable £2179. Example boiler: Worcester Bosch 25si.**

Who is the cheapest boiler company to buy from?

The answer to the all-important question – who is the cheapest boiler company is, of course, WarmZilla. We offer the best value on boiler packages which include everything you need including a new boiler, boiler installation, guarantee between 5-10 years, smart thermostat, system filter, system cleanse and any extras like flues/plume kits that you may need.

We check competitor prices regularly to ensure we offer the best value for money on your new boiler and in addition, we offer a ‘Best Price Guarantee’ (see below).

Whilst we strive to offer the best prices for our customers it doesn’t come at the cost of quality, as you can see from our Trustpilot reviews. Our aim is to offer an easy-to-use service that allows our customers to easily buy a new boiler without needing a degree in boilerspeak, at a price that is affordable and fitted at a time that’s convenient to you.

We’re sure there are a lot of companies that claim to offer the cheapest boilers so we did a bit of research for you. In the table below we compared our prices with that of two of our online competitors and one more traditional boiler installer.***

Online Competitor 1£1,995£2,070£2,795
Online Competitor 2£1,985£2,035£2,785
Traditional Boiler Installer£2,500+£2,500+£3,500+

Prices are based on the following models:
Combi – Worcester Bosch 30i with Horizontal flue
Standard – Worcester Bosch 18 Ri with horizontal flue
Conversion (back boiler to combi) – Worcester Bosch 30i with Horizontal flue

Not only are WarmZilla prices cheaper in general but on the standard boiler, we offer a Hive thermostat where our online competitors don’t offer a smart thermostat at all.

Best Price Guarantee

Our team is always ensuring our prices offer our customers the best value for money. We are so confident that our boiler prices are the cheapest that if you find a lower price, we will promise to beat that quote by £50.

This is the WarmZilla ‘Best Price Guarantee’, if you find a cheaper boiler quote on a like-for-like boiler elsewhere, we will beat it by £50. 


There is a lot of information to take in when buying a new boiler but if you have read this article you are now a fully-qualified boiler ninja. You have all the information necessary to make an informed decision about what boiler you want to buy.

We would advise your boiler package should include the following:

  • Gas-Safe installation
  • guarantee/warranty length you’re happy with
  • System filter
  • Smart thermostat
  • System cleanse
  • Gas pipe upgrade if required
  • Fixed price with no sneaky extras to be added

Check the reviews of any company you plan on getting in to fit your boiler as it is an appliance that is so important to your home and it’s important you get the right boiler company for the job.

If you would like an online boiler quote in just a few minutes then get a boiler quote from WarmZilla now.


*Source, Which? Website
**WarmZilla are approved and regulated by the Financial Conduct Authority (F.C.A) FRN 815093 for credit broking (not as a lender) and offers credit products through a panel of lenders. Finance available subject to status. Terms and conditions apply. Any credit is subject to status, affordability, and a credit check.
*** Prices correct at time of blog publication (30.06.20)

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