Is this the year to invest in a brand new combi boiler for your home?
Across the UK, over one million homes and flats will benefit from the warmth and hot water a new environmentally-friendly combi boiler will deliver. With the government proposing to ban all new gas boiler installations by 2025, the time you have to get one for your home may well be running out.
With so many different types of boilers and so many companies wanting to install your boiler for you, how do you compare boiler prices to get the best deal for you and your family?
The two main types of boiler most commonly installed in UK homes are combination (combi) boilers and conventional (traditional) boilers:
Combi boilers are the more popular type of boiler. Unlike conventional boilers, they don’t need a hot water tank to work.
Combi boilers heat water directly from the mains supply, and it’s this instant heating of your mains water that gives homeowners as much hot water as they want on demand.
With a conventional boiler, once the hot water tank is empty, you must wait for it to fill up again before hot water comes through your taps again.
In this article, we’ll be covering how much a new combi boiler costs, what affects the cost of installing or replacing a combi boiler, how to choose the right boiler for your home, whether or not a combi boiler is the best choice for your home, how to save money on a brand new combi boiler, what’s involved in installing a new combi boiler and how to find and hire a professional to instal a combi boiler.
If you think the time is right to upgrade your heating system, keep reading to find out our top tips to keep it as cost-effective as possible.
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How Much Does a New Combi Boiler Cost?
Depending on the size of your home, the number of bedrooms, baths and showers, the output you’ll need from your new boiler will differ.
Below are some estimated costs for new combi boilers separated by house size:
| House Size | Estimated Cost Including Installation |
|---|---|
| Flat, 1 bed + 1 bath | £1,595 to £2,495 |
| Flat, 2 bed + 1 bath | £1,595 to £2,495 |
| Flat, 3 bed + 1 bath | £1,595 to £2,495 |
| Bungalow, 2 bed + 1 bath | £1,595 to £2,495 |
| Bungalow, 3 bed + 1 bath | £1,595 to £2,495 |
| Bungalow, 4 bed + 1 bath | £1,595 to £2,495 |
| Terraced house, 2 bed + 1 bath | £1,595 to £2,495 |
| Terraced house, 3 bed + 1 bath | £1,595 to £2,495 |
| Terraced house, 4 bed + 1 bath | £1,595 to £2,495 |
| Semi-detached house, 3 bed + 1 bath | £1,595 to £2,495 |
| Semi-detached house, 4 bed + 2 bath | £1,995 to £3,225 |
| Semi-detached house, 5 bed + 2 bath | £1,995 to £3,225 |
| Detached house, 3 bed + 1 bath | £1,595 to £2,495 |
| Detached house, 4 bed + 2 bath | £1,995 to £3,225 |
| Detached house, 5 bed + 2 bath | £1,995 to £3,225 |
Starting with the smallest properties, for flats of between one and three beds and one bath, you can look to spend between £1,595 to £2,495 on a new combi boiler with output to sufficiently cover your living space.
This is the same for bungalows of between two to four beds and one bath; your costs will be between £1,595 to £2,495 depending on the brand and model you choose.
Terraced houses will have a similar range of between £1,595 to £2,495 to suit homes of between two to four beds and one bath.
When we look at semi-detached houses, the prices change slightly when a second bathroom is introduced. For a three-bedroom with one bath, you can still expect the £1,595 to £2,495 price range, but for four to five beds with two baths, the price range will alter to be between £1,995 to £3,225.
Finally, for detached houses the price will increase with the addition of more bathrooms, so for a three-bed, one-bath you can expect to pay between £1,595 to £2,495, and four to five beds and two baths will be between £1,995 to £3,225.
Most boilers can usually be installed in one day and perhaps two days if new or additional pipes are required in the event you need your boiler position moving, or an additional one added to heat your home.
In addition to paying for your boiler, you’ll also need to pay your fitter for the installation. Below, we’ve included a general idea of the type of budget you’ll need for the installation:
| Job | Estimated Cost |
|---|---|
| Boiler Installation | £630 to £780 |
| Moving Pipework | £190 to £310 |
| Chemical or Magnetic Clean | £440 to £535 |
| Total Estimated Cost | £1,260 to £1,625 |
A typical boiler installation will cost between £630 to £780, and the cost of moving pipes will be between £190 to £310 depending on the amount of work needed and how easily accessible that location is.
If your new boiler is replacing a very old boiler, your installer may recommend that they perform a mechanical flush on your system before fitting your new boiler.
This will get rid of all the gunk in your heating system so that when your new boiler installation has been completed and you start using it to provide heat to the radiators, you can better control the temperature output of each radiator wherever located in your home.
For a mechanical flush before installation, you can expect between £440 to £535, with all three elements totalling between £1,260 to £1,625.
Click To Get QuotesWhat Affects the Cost of Installing or Replacing a Combi Boiler?
Further to the cost of the boiler itself, and the installation, there are a few other factors that impact the cost of installing or replacing a combi boiler.
If you’re working to a strict budget, get to know these elements that can alter your final price:
Boiler Manufacturer
One of the first options that can change the cost of your new boiler is simply the manufacturer you choose.
Some are much cheaper than others – brands like Main at £500 to £550 and Ferroli at £700 to £850; while other manufacturers can be much more expensive like Keston at between £1,200 to £1,350, or Viessmann which can reach a total of £2,750.
Estimated supply cost of combi boilers by the manufacturer (note: prices include VAT)
| Manufacturer | Estimated Supply Cost |
|---|---|
| Baxi | £600 to £1,500 |
| Glow-worm | £700 to £1,700 |
| Ferroli | £700 to £850 |
| Ideal | £550 to £1,500 |
| Keston | £1,200 to £1,350 |
| Main | £500 to £550 |
| Potterton | £900 to £1,100 |
| Vaillant | £700 to £1,800 |
| Viessmann | £800 to £2,750 |
| Vokera | £500 to £1,200 |
| Worcester Bosch | £750 to £2,500 |
In most cases, the manufacturer is just a name attached to the boiler and doesn’t impact the efficacy of the output. Some manufacturers will carry better warranties and insurances than others, so that’s something to bear in mind when picking the right one for you.
Deciding on the company you trust and you want to instal your boiler is important in securing the best deal for you at the right price with an assured level of after-sales care in the rare event that things go wrong.
You could potentially be paying more upfront to get the boiler installed, but you may be saving on warranties if there are issues within the first few years – something which cheaper manufacturers might not carry themselves.
Moving Your Boiler
If you want to move your boiler from one location in your home to another, you’ll need to add extra gas pipes to route the fuel to the boiler, which can quickly become expensive.
You’ll also need to factor in the cost of making good after the new pipes and boiler are fitted in your home, such as covering walls or replastering where things have been inserted, all adding to your project’s cost.
In most instances, it’s not necessary to move the boiler unless you’re remodelling the layout of your entire home. In most circumstances, it’s recommended that you keep the boiler in its original position.
Pipe and Flue Upgrades
Another cost can come from if you need to upgrade your pipes to current standards if you have particularly old fittings. These can range from between £250 to £400, and depending on how much you need, can greatly increase your project’s fee – but it’s an inescapable fee in most cases.
Similarly, if you need a new flue fitting that’ll cost you between £300 and £600.
Accessories
Moving into the optional extras territory, if you want to upgrade your home heating system to include smart controls and thermostats, you’ll be looking at costs of between £100 to £300, depending on what you choose.
If you want to include a magnetic filter to stop debris from entering your boiler system and clogging it up, that’ll be between £100 and £200 to have installed.
Radiators
You may want to upgrade or replace your radiators in your home once you’ve got a new boiler to make the most of your new system. This can range from between £170 to £370 depending on size, including installation.
If you want to keep your current radiators but you want to move them to a different location in a particular room, there may be more to pay. Moving the position of your radiators will require your fitter to move your pipes, for which you should budget between £190 and £310.
For more information on radiator costs, see our dedicated page on it here.
Local vs National Installer
Unsurprisingly, national installers will cost you more than local traders. This is because local traders won’t have the running costs to uphold like nationals – things like showroom running costs and helpline fees.
Where possible, find a local trader who has worked on properties in your area and that have good reviews from trusted members in the community.
How Do I Choose the Right Boiler?
A big advantage of combi boilers, particularly given that UK homes are some of the smallest in the world, is their size – most people have them fitted snugly in their kitchen hidden away behind a cabinet door.
There are situations where an installer may recommend a conventional boiler if you have a particularly large home. However, given recent development in technology, manufacture, and production, your installer is likely to recommend a combi boiler for your home or flat.
Boiler Comparison by Output Size
There are three main groupings of boiler by output. Those boiler groupings are:
- 24-27kw combi boiler
- 28-34kw combi
- 35kw+ boiler
When you instal a new, state-of-the-art combi boiler, one of the most important and the quickest benefits your new boiler will deliver to you and your family (other than on-demand heating and hot water) is a substantial reduction in your gas bills.
The closer the output size of your chosen boiler to the actual needs of your household, the further your gas bills will reduce. Together with your installer, it’s important to make sure that you choose the most suitable boiler for the job.
24-27kw Combi Boilers
These are best suited for small properties with up to ten radiators and one bathroom.
For smaller homes, you should budget between £625 and £6,190 if you choose a boiler from Potterton, Glow-worm, Ideal, Worcester Bosch, Valliant, Baxi, or Viessmann, remembering to factor in an additional £1,260 to £1,625 for installation costs.
28-34kw Combi Boilers
28-34kw combi boilers are particularly suitable for medium-sized properties with two bathrooms and up to 15 radiators.
You should budget between £500 and £2,800 for the boiler itself plus the cost of installation on top.
35kw+ Combi Boilers
For larger properties, a 35kw+ boiler will provide the right balance of heat, hot water, and gas bill savings – you should expect to put aside between £745 and £2,000 for the supply of a boiler of this power.
They’re ideal for large properties with up to 20 radiators and two or more bathrooms.
If you’re unsure of which boiler is right for your home, use this calculator from Which? to help you choose the correct boiler output and size for your property.
Is a Combi Boiler the Best Choice for My Home?
As we’ve mentioned, the combi boiler is not the only option available to homeowners wanting a sufficiently heated home – there are also system boilers to consider.
Here are the pros and cons of combi and system boilers:
Advantages of Combi Boilers
- Cheaper heating bills: combi boilers are more heat efficient than alternative models and can save you reportedly up to £300 per year on heating bills
- Faster water on demand: there’s no tank to fill up with water and then heat like traditional boilers, so you have fast hot water on tap – literally!
- Simple to service: their manufacturing process means they’re easy for specialists to service and faster to correct if issues arise
- Water directly from the mains: which makes it cleaner than other models that store water in a tank. You’re also less likely to suffer pressure issues for the same reason
- Compact and no need for a water cylinder for hot water
Disadvantages of Combi Boilers
- Reliant on good water pressure: which is something to check before you get a combi boiler fitted. The efficacy of your system will be reliant upon your area having good water pressure, so check this before getting anything installed
- If it fails, you’ll be without hot water: no water tank means no hot water will be stored in the event the boiler breaks down, so you can be left without hot water until it’s restored
Advantages of System Boilers
- Hot water is always available
- Affordable to run and environmentally friendly owing to good energy efficiency
- Run both bath and shower at the same time and maintain water pressure – unlike with combi boilers
- Easy to program to ensure there’s enough water ready for when you’re likely to need it
Disadvantages of System Boilers
- Insulation may be required: to keep the hot water tank hot, extra insulation may be needed around the tank to ensure the heat doesn’t escape
- Hot water is often reheated: meaning it’s not always the cleanest supply as opposed to coming straight from the mains supply as in combi boilers
- Space needed for a hot water cylinder: making it not as space-efficient as a combi
How Can I Save Money on a New Boiler?
Now you’re clued up on what boiler you might want, here are some ways to ensure you’re getting the best deal possible when looking to buy your new boiler.
Do You Qualify?
First of all, it’s best to check whether you might qualify for a free boiler through the government’s Energy Company Obligation scheme.
Under the free boiler scheme – ECO (Energy Companies Obligation) – low-income households could be entitled to upgrade to an energy-efficient boiler free of charge, or at the very least, heavily subsidised. Landlords with low-income tenants may also be eligible.
Full information on this scheme is available on this page.
Boiler Cover
If you already have boiler cover, it’s worth asking your provider if they offer a discount on a replacement.
If you don’t have boiler cover and would like to learn more about what different providers offer and how much they charge, visit our detailed boiler cover guide.
Local vs National Chains
When looking for someone to fit your new boiler, it’s best to always consider a local heating engineer over a national chain. This way, you’ll be supporting local businesses but also stepping away from the inflated prices that national chains sometimes charge.
While you should get as wide a range of quotes as you can from both local and national installers, bear in mind that you may save up to 40% on the cost of your boiler and its installation by choosing a local company. That’s because they employ fewer people and they have far smaller overheads than the big national firms.
Instead of paying for the upkeep of their showrooms and helplines, you’ll just pay for what you buy, and the labour incurred in the fitting.
Shop Around
It’s no secret that the key to getting a good price lies in shopping around for the best deal possible.
When collecting quotes, be sure to let your contractors know that you’re asking others for prices too as this will help them to vie for your business and usually drop their prices to be more competitive.
It’s a little more time-consuming, but it pays your rewards in dividends in the end.
Click To Get QuotesWhat’s Involved in Installing a New Boiler?
The old boiler will be removed first to create room for the new model. A flush of the system will then happen to rid the system of any leftover debris from years of use.
If necessary, any new pipes will be installed to ensure there’s sufficient water flow to your new boiler, including any necessary upgrades. This can also include additional radiators or movement of existing radiators if required.
The new boiler will then be fitted, and the system will then be checked by the heating engineer to make sure everything is in working order before handing it over to you and registering any guarantees or warranties from the day of fitting.
How Do I Find and Hire a Heating Engineer?
In the first instance, it’s best to seek recommendations from family, friends, and neighbours. Has anyone had their boiler replaced recently and had a good experience?
They’re likely able to pass on the details of their heating engineer to you.
This way, you can safely side-step any rogue traders and get someone who has been vetted by your acquaintances – and hopefully is of a good standard because they wouldn’t recommend them if not!
You can also check the Gas Safe register to find individuals who have all the credentials to ensure they’re safe for you to hire for your boiler replacement job.
Another way to find a trader is to use HouseholdQuotes which will save you from swapping between lots of website tabs to find the right contractor for you – and in most cases, it’ll help to save you up to 40% on your project fee.
HouseholdQuotes helps homeowners ready for boiler installation by helping them lock in the savings by encouraging competition between these companies. When we pass a homeowner’s details onto them, these installers know that they are one of three or four companies competing for your order.
They don’t want to lose out so they’ll often do the work for a substantial discount so that they can keep their fitting teams busier. All of our installers are registered with Gas Safe and they have a proven trading history – ideal for your peace of mind so that you know you’ve chosen the right people for the job.
Click To Get QuotesEnsuring the Professional Is the Right Fit
One of the first questions when dealing with a contractor to fit your new boiler is simply to find out if they’re Gas Safe registered. This is so important as boiler installations can be dangerous if not done properly, and this step isn’t something you should ever miss out on.
Secondly, get a written quote. This will stop you from being overcharged or having things left out of your original quote if everything was just done verbally.
If a contractor refuses to give you a written quote, it’s usually a red flag and it is best to not continue communicating with them as they may be using this as leverage to trick you into paying more further down the line.
Seeking out their experience, and any relevant references from those who have had work done recently, is a great way to make sure what you’re buying into is legitimate and of good quality. If your friends have used someone recently, ask if you can go and see their work inside their home to make sure you’re happy with the quality.
Finally, all Gas Safe registered heating engineers should have insurance as standard, but it’s good to make sure you check this before entering work with them.
All new boilers should also carry a manufacturer’s guarantee, so make sure you check this out before getting anything fitted and make sure your installer follows all the steps to make sure that guarantee is valid.
Final Checklist
Are you ready to upgrade your boiler? Here are our final points to make sure everything is taken care of when taking on this project:
- Check your warranty: are you eligible for a free upgrade from your existing boiler provider?
- Are you eligible for a free boiler through the government scheme?
- Which boiler is best for you: does a combi or system suit your family’s needs more?
- Figure out the output you need based on how many bedrooms and bathrooms you have
- Find a reputable trader using HouseholdQuotes to help you save up to 40% on your project’s fee
- Make sure the contractor is on the Gas Safe register and has relevant insurance before agreeing to any work.
Click To Get QuotesFrequently Asked Questions
What’s the Difference Between a Combi Boiler and a Conventional Boiler?
Conventional boilers work by heating water in a water cylinder and can power a shower and a bath simultaneously. However, you have to wait for the water to reach temperature, and your hot water supply can ‘run out’ until your cylinder has re-heated sufficiently.
Both have their pros and cons, as listed earlier in this article – choosing what’s right for you and your family is entirely up to your circumstances.
What Is a System Boiler?
For full information on system boilers, see this article.
Can a Plumber Install a Boiler?
To instal the actual boiler, only Gas Safe registered heating engineers can undertake the job as it is a high-risk job, and involves more than just water.
When looking to hire someone to fit your new boiler, ensure they’re listed on the Gas Safe register and have relevant insurance to cover both themselves and you in the event of something going wrong during or after the fitting.
Usually for boiler warranties to be valid, you’ll need to enlist a heating engineer to fit the boiler to the correct standards, else any guarantees of free repairs or replacements within a certain timeframe may be invalid due to incorrect fitting procedures in the first place.
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