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Boiler Replacement Cost Guide for 2021

Need to check whether you need a new boiler or fix your old one? Our dedicated boiler replacement cost guide will ensure those experiencing boiler trouble will get their answers.

Boiler Replacement Cost Guide

With so many providers and options on the market you’re probably at least a bit confused. I mean, how do you choose between British Gas, Help-Link, local installers or quote comparison websites, since everyone promises the best prices?

Luckily, we’ve done the research for you. This way, you can make an informed decision on the boiler brand, model, financing options, installation company, and whether you even need a replacement in the first place.

If you’re in a hurry, go get an exact quote in 90 seconds by filling this online form from Heatable — which we’ve found offer the best service by installing Worcester Bosch boilers for fixed prices starting at £1,595.

Heatable new boilers

If you’d rather read on, know that we contacted local Gas Safe engineers and companies installing the types of boilers mentioned above, and came up with some estimates of labour prices for boiler replacement. Our findings promise to give you a rough idea whether the quote you’re being offered is actually a rip-off or not.

How much does it cost to replace a boiler?

Your boiler replacement cost can be influenced by SO many factors. But since I know for sure you’re more interested in actual numbers, here is a rough estimate of costs based on a reputable boiler brand in the 24-30kW range.

Combi Boiler Replacement Costs  — £1,900-£2,300

If you’re planning to install your new boiler in the exact same spot its predecessor occupied, then you’ll pay somewhere around £1,900 for the entire job. 

On the other hand, if you plan to move the boiler to a new location in your home, be ready to part ways with a few hundred quid more. Because of the inherent complexity of relocating a heating system’s infrastructure, you can expect to pay at least £2,300 for this project. 

If you’re lucky enough to live in London, you can add about 8-10% to the figures above to get your ballpark estimate. 

Regular Boiler Replacement Costs — £1,900-£2,350

If you feel that a regular boiler is the more fitting option for your household, good news — you should be able to get one for the same price as the smaller combi, roughly £1,900. That said, your relocation will cost around £50 more, just because regular boilers are more cumbersome and their installation demands more time and effort. Again — Londoners, sorry, but you’ll have to tack on an extra £100-£150 to these numbers. 

Costs of Conversion to a Combi Boiler or System Boiler — £2,700-£3,200

Upgrading to a combi or system boiler costs quite a bit more than a one-for-one replacement. If you currently have a regular or back boiler, the infrastructure upgrades needed to accommodate a combi can easily add an extra £1,000 to the overall replacement costs. Here’s a quick summary of what you can expect to pay for such an upgrade (new boiler included):

Work Required

Boiler Type


Central heating system upgrade to a combination boiler (including removal of hot water tanks)

Regular Boiler


Back Boiler


Upgrade to a system boiler (retaining hot water tanks)

Back Boiler


Boiler replacement cost comparison

Most local installers will quote you more or less what you see in the table above. I know some of you might say that large national installers can sometimes give you better prices considering their discounts on the purchase cost of the boiler itself. While that is somehow correct, it doesn’t take into account the high overheads of these companies with fitting costs skyrocketing to the roof.

That’s why we need to compare apples with apples. To give you an idea of what you should expect when working with a larger scale provider of boiler replacements, we decided to take a deeper look into what British Gas, Heatable and Help-Link can do for you. They are not ranked in any way, so seeing BG here first doesn’t mean they are the best or worst, cheapest or most expensive.

Get Heatable boiler prices on screen

British Gas replacement costs

British Gas have been installing boilers for more than 50 years. They promote themselves as the company who “fit more boilers than anyone else in the UK”. Other than a range of boilers that are exclusive to British Gas, they have connections with top manufacturers and also install Worcester Bosch, Vaillant or Glow-worm boilers.

But that doesn’t mean you’ll be getting the best offer. In fact, people often talk about them as the most expensive in the market — as in, expect to pay a 40-50% “fee” to have your boiler installed by British Gas.

It’s quite easy to understand why BG will quote you higher than other companies in the market. They invest a lot in marketing — all those adverts with cute animals or the spinning planet you see on TV must be paid by someone — plus have a lot of overhead costs that they must charge onto the final consumer.

And if you needed more proof, Help-Link, which are a direct competitor, promote to save you ~ £1,081 compared to British Gas.

Heatable replacement costs

How would you like to save more than £1,000 by installing a high-quality Worcester Bosch boiler with 10-year warranty included, and get a FREE WiFi thermostat with all selected combi boilers? Sounds like a great deal, no?

A little bit of background to understand how this is possible. Heatable have shaken the boiler replacement industry by providing a highly technical online solution that quotes you fixed prices for your job, as low as local installers.

What kind of fuel does your boiler use?

Grab your fixed price online by 3PM, and get next-day boiler installation.

Worcester boilers installed from as little as £1,795.

We went through their quoting process — takes less than 90 seconds — and found out that their solution gives lots of different boiler prices  — about 10 in total for the 3-bedroom property we queried for.

To get a rough idea we answered the Heatable form in such a way that no additional work would be required except for the Worcester Bosch 25i to swap the old boiler we had. The cost was £1,649 with installation, which is nothing short of amazing. Of course, you could scroll and get the 30i which is a Heatable “Best Buy” and overall the most popular unit in the UK, but you’ll need to add some more ££.

HEATABLE Worcester Bosch Greenstar i 30kW

Check out on-screen boiler installation costs using this quick form (no contact details needed).

Get Heatable boiler prices on screen

Help-Link replacement costs

Help-Link provides online quotes for new boiler installs.

Their online form is just as simple as Heatable- but with a twist. It won’t put prices in front of your eyes at the end unless you give them personal info such as phone number or email. I found this a bit annoying but went on.

The form was filled in with all the simplest info so that it’s only a boiler swap rather than a new system with all sorts of upgrades. The results didn’t impress us. I mean, we’re looking at just over £2,100 for an Ideal boiler with a 5-year warranty, and just over £2,600 for the Worcester with 10-years warranty.

That’s more expensive than the other option we tried, Heatable — which is quite ironical.

Our thoughts on the matter

Large national installers will always be more expensive than local installers. The alternative is quote comparison site, Heatable, where you get a fixed priced so you don’t have to worry about upgraded controls, boiler filters and more. They also promise hassle and mess free installation, the next day you order (or whenever you choose).

Do I need to replace my boiler?

It’s not just you, many people ask themselves “How to tell if my boiler needs replacing?”. The answer is not as simple as you may think mainly because of the misconceptions that when a boiler is of a certain age it needs to be replaced. Just like people, if you take care of them, boilers can live well into old age.

We’re not saying you should do that – sometimes there’s no alternative and you must replace it.

If you check may of the things below, then it’s a clear sign replacement is needed:

  1. Bills are exploding — it’s not just service and repairings; with an A-rated boiler you could save around £200 a year and help the environment
  2. Often breakdowns — one of the reasons for higher bills
  3. Boiler leaks and the cost of getting it back in shape is not worth the investment
  4. Replacement parts are hard to find — your boiler is probably very old
  5. Boiler or radiators are noisy — this may be fixable, but it may be that you need to weigh up what you’re spending
  6. Blue flame, now yellow — a sign that a Gas Safe engineer should pay you a visit, immediately.

Get Heatable boiler prices on screen

Boiler Replacement Cost FAQ

Which is the best boiler to buy in 2021?

We recommend Worcester Bosch boilers (the 25i and 30i combi boilers rank highest on our list). That’s because they are the most reliable brand throughout the UK market.

How long should a boiler last?

On average boilers should last 10-15 years. If they are older or out of warranty, or if you constantly get repair bills to bring it back in shape, it might be wiser to have it replaced with a newer, A-rated model.

How much does it cost to replace a boiler in a house?

From our research, the lower end is just around £1,795 for combi boiler installation with 10-year warranty included, while larger properties who require larger boilers could extend to £2,500.

How long does it take to change a boiler?

It depends on the complexity of the job: 1 to 3 days. A simple swap with no new upgrades shouldn’t take more than 1 day. However, if you need to upgrade the pipework or you’re replacing a combi boiler or a central heating system it could take up to 3 days.

Is British Gas a rip-off?

It’s not fair to call British Gas a rip-off. But, it’s a fact that their installation works are more expensive than local installers or online businesses such as Heatable where overheads won’t inflate your price without the need of it.

How can I get a boiler for free?

You could receive a free ECO (Energy Company Obligation) grant if you meet certain criteria. Typically it’s only pensioners who get a boiler for free via the ECO scheme. Read more about getting a free boiler here.




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