Guide to Boiler Replacement Costs

Investing in a new boiler is a big decision. You want to make sure it’s the right boiler type for your home – and that it’ll last. Then there’s the boiler replacement cost.

In this guide, we’ll explore how much a new boiler costs, the installation cost and some tips on choosing a new boiler and what to expect during a boiler installation.

Do you need to replace your boiler?

Before we dive into the nitty-gritty of boiler replacement costs, consider first whether you really need to replace your boiler. Has it stopped working or is there a fault that can be repaired? If there’s a leak or the boiler pressure has changed, you might be able to fix it yourself.

boiler engineer servicing a gas boiler in a home

How often should I replace my boiler?

Most people in the industry expect a boiler to last 10-15 years – assuming it’s been looked after and serviced regularly. So you shouldn’t need to replace your boiler more often than this.

If your boiler is only a few years old and something goes wrong, check whether it’s still covered by the manufacturer’s warranty. If it’s the first time a fault’s occurred, read our 10 common boiler problems to see if you can fix the fault yourself. If not, get it repaired by a qualified engineer.

Generally, there are some clear signs that indicate it’s time to replace your boiler:

  • Are you having to call out an engineer to fix the boiler more than once a year?
  • Is it getting expensive to buy replacement parts? Or do you have to wait a long time for these because they’re not easy to find?
  • Have you extended your home? If your rooms aren’t now as warm as they used to be or you’re not getting enough hot water, it could be time to upgrade your boiler.
  • Have your bills become more expensive? This might not be the fault of the boiler. But it’s widely recognised that an older boiler doesn't always work as well as a newer model – particularly if it’s not a condensing boiler – so it might cost more to run.

Save more than £300 when you replace your boiler

Perhaps you’re renovating your home and want to invest in a more energy-efficient heating system. So that you can enjoy a warmer home and hot water without spending more on your heating. The Energy Saving Trust estimates that families in a detached house can save up to £315 a year by upgrading from a G-rated boiler to a new A-rated condensing boiler.

If you’re not sure what the energy efficiency rating is for your boiler, check the ErP label that came with it. A-rated boilers are the most efficient, with G-rated the least. And you can expect any new boiler to have an A-rating these days. This means they don’t waste as much fuel in providing heat and hot water to your home as older models. Which means you won’t pay as much for your heating and hot water. So you’ll definitely make savings in the long run on your energy bills. Read more about ErP in this guide from our boiler partner, BOXT.

Do I need to replace my boiler with the same model?

There are all types of boilers available – and you don’t have to replace like-with-like. In fact, it’s best to review your options afresh, because modern boilers are far more efficient.

For instance, if you had a non-condensing boiler before, your new gas boiler is likely to be a condensing model, since these became law from 2005. Their design means they don’t lose as much heat as non-condensing boilers. So they won’t cost as much to run. Read more about the main types of boilers in this guide.

What if I have a back boiler?

If you live in a property with a back boiler, you won’t be able to replace this with the same type. Back boilers are a very old type of boiler. They became popular in the 1960s and were fitted behind a gas fireplace. But because they’re nowhere near as good at stopping heat from escaping up the chimney, you won’t be able to replace your back boiler with a new one. So you’ll need to remove – or, at the very least, disconnect – the old system and replace it with a new type of boiler. Get more advice on back boilers from the original manufacturer of them: Baxi.

Worcester Greenstar CDi Compact Combi Insitu boiler

How much does a new boiler cost?

The cost to replace a boiler varies enormously – starting anywhere from £1,500 up to more than £3,000.

Your boiler replacement cost depends on a number of factors:

  • The size of your home and family: unsurprisingly, more powerful boilers (those that have a higher central heating output) cost more.
  • The type of boiler you choose: not just the brand of boiler, but whether it’s a combi or conventional (standard) or system boiler.
  • The hot water flow rate on a combi: this is how quickly it heats and supply hot water.
  • The warranty: a boiler with a longer warranty typically costs more.
  • The set-up of your home: conventional boilers come with two tanks, as well as the boiler. And they’re typically stored separately in a loft and airing cupboard. So you need to factor in the space required if moving from a combi to a conventional or system heating system.
  • Whether you have solar water heating: These are panels installed on your home’s roof that generate hot water from the sun. And they work best with a conventional or system boiler, because the hot water generated has to be stored for later use in a tank. A combi boiler, on the other hand, doesn’t come with a tank – but instead heats water as and when you need it.
engineer responding to an emergency boiler repair

Boiler installation costs

It’s not just the new boiler cost you need to consider. There are also the costs associated with replacing your boiler, such as the boiler installation cost. A Which? investigation found that boiler installation costs could vary by as much as £3,200!

Fitting prices will differ, depending on:

  • The amount of work required – are you reconfiguring your heating system? The installation cost for replacing one combi with another is inevitably going to be less than replacing a conventional boiler with a combi, for example. Or does the installation require other services? For instance, scaffolding to get on the roof if that’s where your flue is located (this is the pipe that releases exhaust gases from the boiler outside)?
  • The type of installer – always look for a Gas Safe Engineer to install your boiler replacement.
  • Your location – this might be due to the availability of installers or regional variations in installation costs.

Sometimes the boiler installation cost is rolled into the total figure quoted – like you get through our partner, BOXT. The benefit of this is there are no hidden surprises. For example, BOXT’s fixed price can include everything from boiler and pipework installation (including any alterations or upgrades); the removal and safe disposal of your old boiler; a MagnaCleanse system flush (see below to find out what this is); magnetic filter and chemical inhibitor (see below) and any new flue and brickwork required.

Other boiler replacement costs to consider

If you’re spending hundreds of pounds on a new boiler, you want to make sure that it’s going to work the best it can! So there might be some extra boiler replacement services you want to consider:

An extended warranty – Many top-brand boilers come with 10-year warranties. But if yours doesn’t, consider paying extra to extend the warranty beyond its usual period. A warranty – otherwise known as a guarantee – gives you peace of mind that if your boiler develops a fault, the manufacturer will repair it for you.

New equipment – To get the most out of a new boiler, consider investing in smart controls or thermostatic valves to control your heating in the most efficient way possible. And make sure you’re not wasting money by heating empty rooms. You might also want new radiators if they’re old or don’t work with your new boiler.

A system cleanse – Also known as a power flush (or MagnaCleanse system flush from our partner, BOXT), this is a way of clearing out any rust and debris that’s gathered in the heating system, pipes and radiators. Installers – like BOXT – include this as part of their installation. So there’s nothing clogging up the central heating system to prevent your new boiler from working properly.

A magnetic boiler filter – This is another clever tool to keep your system free of sludge. It attaches to your central heating system and uses its magnetic powers to attract metallic particles. So they can’t get in the way of the flow of the water and clog up your system. Find out more here.

Can I replace my boiler for free?

If you’re on a lower income, you might be able to pay less to replace your boiler. Find out whether you qualify for the Government’s Energy Company Obligation (ECO) scheme here.

How to get help with your boiler replacement cost

1. Is it still under warranty?

Some boilers come with warranties of 10 years – and the manufacturer will replace your boiler if it fails in that time. As always, check the small print of every policy – some charge a call-out fee. Others will bill you for installation. And always make sure you register the warranty as soon as your boiler is up and running (most have to be registered within 30 days).

2. Do you have boiler insurance (also known as boiler cover)?

If you’ve taken out an insurance policy to protect your home against boiler breakdown, you might be able to get some help with the cost of a replacement boiler. 


3. What about your home insurance?


Some home insurance plans come with extra services, like home emergency cover. These typically cover things like repairs to your boiler if it breaks down in winter. And they may include a payout should you need a replacement boiler[2]. But it definitely pays to read the small print on all your policies, as some specifically exclude boiler replacement. All will have certain conditions you need to meet too – like servicing your boiler every year (and keeping proof of this).

4. Pay monthly for a new boiler

If you can’t afford the upfront boiler replacement cost, some providers will let you pay for it in monthly instalments instead. Essentially this is a type of loan – much like how you pay for your mobile phone. With a pay monthly deal, you spread the cost of the boiler over a fixed number of months. Bear in mind though there’ll be some interest you pay back each month too, so your total cost is likely to come in higher than the original boiler fee. Take a look at what’s involved through our provider, BOXT.

5. Rent a replacement boiler instead

You can rent your home and car… so why not your boiler too? The advantage of this is that you have a fixed monthly cost. There might not be any interest – but you’ll need to put down a deposit. And if you’ve ever struggled to pass a credit check, that might not be a problem when you rent your boiler. But as with any rental agreement, make sure you check any small print for the full details.

6. Look out for special offers

Admittedly, this isn’t a way to lower your boiler replacement cost. But given the high upfront cost for a new boiler, it’s worth checking if there are any deals or special offers available. At EDF, we often have special offers on smart home products when you take out a new boiler through us. Find out more here.

7. Should you buy a secondhand boiler?

Occasionally you might find a secondhand boiler listed on Gumtree or eBay. But it’s not always a good idea to buy it, especially if you don’t know the boiler’s history. Most people don’t replace their boiler unless it's broken or not working very well. Then there’s the cost of installing it – and paying for future servicing and maintenance. So be very wary of buying secondhand. One alternative to consider is a trade-in deal. Some boiler installers will give you a discount on your new boiler as payment for your old boiler. So ask if this is an option when you’re shopping around.

How to get the best boiler replacement deal

We’ve teamed up with BOXT to help you get a brand new boiler for the best price possible. They offer a unique price promise – which includes parts, labour and warranty. Plus they’ve been rated number one for gas installation and heating service on Trustpilot. And if you need a boiler pronto, they do next day installation.

new boiler in a kitchen

How to choose a replacement boiler

Work through our checklist to make sure you find the best boiler for you:

  • What size boiler do you need? By all means pay out more for a better quality brand, but don’t super-size a boiler for the sake of it. Too big and you’ll end up paying for energy you don’t need. Too small, and you might end up with a cold shower after the kids have been in the bath. Get more advice in this size guide from our partner, BOXT.
  • What type of boiler works for your home? From combi boilers to conventional boilers, system boilers to back boilers… there are a range of boiler types out there. Find out which is right for you.
  • What fuel type do you use? If you’re replacing a gas boiler, the obvious choice is to replace with another gas boiler. Especially as gas is cheaper than other fuel types, like oil and coal. But consider if you might want to switch to electric and modern-day storage heaters. Or a low-carbon option, like air source heat pumps. Particularly as the government has said it won’t be connecting new homes from 2025 to the gas grid. Read more in our electric vs. gas heating blog. And get more ideas on how to heat your home efficiently in our energy-efficient heating tips.
boiler engineers installing a new boiler

What happens during a boiler replacement?

Your experience will depend on who’s installing your boiler. But typically the installation will follow these steps:

  • The installer will turn up and remove your old boiler
  • Your new boiler will be fitted – along with any new pipework
  • They’ll test your new boiler and complete any paperwork for you
  • You’ll be shown how to use the boiler, along with any new smart controls

We’ve teamed up with BOXT to offer a fixed-price boiler – including installation. Find out what makes their installations so special.

How long does it take to install a new boiler?

Hmmm, how long’s a piece of string! As with any installation job, it depends on what you’re having done. So if you’re having a straightforward combi replacement boiler, it should only take a day. But if it’s a more complex installation – perhaps you’re replacing a conventional boiler and upgrading your radiators. Or you’re moving the boiler into a new room. It could take two or more days.

Whoever’s carrying out the installation should give you an idea of timescales, what time you can expect them to arrive and the scale of work involved. If in doubt, always ask!

We’ve teamed up with BOXT to give you a replacement boiler at an unbeatable price. Choose the right replacement boiler for you today.