Boiler Installation Cost (Guide): Expert Answer on “How Much to Fit a Boiler”

Need a new boiler and not sure how much you should pay for installation? You’re in the right place — we’ve put together this handy guide to boiler installation cost so you can learn all you need to know before making a purchase.

If you’d like to learn more about the overall expenses that come with getting a new boiler, head over to our full guide to the cost of new boiler replacement. Otherwise, read on!

Boiler fitting cost

Boiler Fitting Cost: Labour Quotes

If you’ve already started getting boiler replacement quotes, there’s a good chance that not one of them is the same.

Different Boilers = Different Installation Costs

Wondering how much does a new boiler cost to install?

Boiler fitters will offer you a wide array of boiler prices. Some of this inconsistency will stem from the actual new boiler costs — for instance, low-end combi boilers could cost as little as £500, whereas a premium brand’s flagship model will have an average cost of £1,000 or more (boiler only).

Type of Boiler May Also Affect Boiler Replacement Cost

Another factor to consider when buying a new boiler is the boiler type.

You’ll typically pay less for replacing a combi boiler for a new one, and more if you’re converting from a system boiler, or heat-only boiler, to a combi or vice versa.

That’s because regular and system boilers require other infrastructure, such as a hot water cylinder, water tank, and pipework, so the gas engineer has far more moving piece with which to work.

This, of course, adds to the cost of labour.

Likewise, system boiler installation will cost a bit more, especially if you’re getting a boiler with a new hot water tank. And if you need to replace an old back boiler with any modern gas boiler, expect to pay at least £700 on top of the fitting costs.

As for most biomass boiler models — these tend to be the most expensive to both purchase and fit.

To summarise: combi boiler costs tend to be lower because these boilers don’t require additional infrastructure.

Other Installation Cost Factors For A Boiler Replacement

That said, prices of materials and components the new boiler installation requires will also contribute to the replacement costs. 

As an example, not ALL boiler fitters will install a magnetic system filter. These filters stop heating sludge from clogging your boiler and central heating system, so they’re a worthy investment. An installation cost quote could be £200-250 higher if it includes a filter.

How Much to Fit a Boiler (Labour Only)?

Expect your new boiler installation costs to be around £350-750 for just labour. This includes copper pipe and fittings for a basic installation in the same location, but not the boiler itself. The other costs missing from the number above are for the flue, magnetic system filter, limescale filter, and more.

There may be additional expenses involved if you wish to move your boiler, too.

Keep in mind that the cost of a new fitted boiler will vary widely depending on whom you hire to perform the installation.

For instance, going with a large, national company is bound to set you back more than opting for a local trade.

You’d also be surprised by some of the generous deals you could get from online installers, like Heatable.

Where to Get New Boiler Pricing

To get a fixed price for all parts and labour associated with installing a boiler, you can use this boiler price calculator on Heatable’s website. Thanks to their low overhead, Heatable usually have attractive prices for most top boiler models, like Worcester’s Greenstar 4000.

Worcester Bosch Greenstar 4000

Do Combi Boiler Installations Differ in Price for Gas, Oil, and LPG?

Typically, we’d not expect combi boiler installation cost scenarios to change based on fuel type. The price for a new combi boiler installation is more likely to differ based on the fitter you use.

However, bear in mind that you’ll need a Gas Safe engineer to install gas boilers, an engineer with Gas Safe LPG accreditation for LPG boilers, and an OFTEC engineer for oil boiler installations.

Also note that larger, oil boilers can be extremely heavy.

Whereas a typical LPG or gas combi boiler might weigh as little as 42kg, oil boilers can be 100kg and beyond.

If you’ve got a large oil boiler, especially in a hard-to-access installation area, you may need 2 or more people to install it. It’s likely your boiler fitter is going to account for the additional cost of having a 2nd pair of hands to help them move and fit the appliance.

What kind of fuel does your boiler use?

Fixed price online with next day installation

Worcester boilers from as little as £1,965.

How Combination Boiler Fitting Cost Is Determined

Obviously, there’s a big difference between paying £350 and £750 for installation — the low and high ends of the spectrum we mentioned above. So, why do installation costs vary so much?

Boiler Weight

As we’ve already mentioned, a heavy boiler is going to mean that the boiler replacement is a two-person job, which will increase costs.

Typically, a single person can perform most gas and LPG boiler installations in residential properties.

For oil boilers, you should expect two boiler fitters to complete the install, increasing overall labour costs.

Complexity Of the Boiler Replacement

Some boiler replacements are straight swaps. That means a few connections are loosened, the old boiler is removed, and the new boiler slots in its place.

In this fortunate scenario, your boiler installer can get right to testing the boiler and sign it off as Gas Safe.

But not all boiler installations are this simple.

If your new boiler isn’t the same as your old one, the engineer might need to change pipework and re-drill holes to mount the boiler.

This all takes time, and that’s going to add to the cost of fitting your new boiler.

Additional Installs

There are a few things that might have been included in your installation quote that are going to increase overall costs for your new boiler.

For instance, if your install quote includes a magnetic boiler filter, or limescale filter, these all need to be fitted. And the cost of fitting these boiler parts can soar into the hundreds, increasing your overall installation cost.

Additional Works

A boiler fitter needs to leave your property in the same state they found it. If the install is complex, they might have needed to drill a new core hole for a flue, remove floorboards, or chip away plaster.

All of these things take time to patch up, and all that time, means more labour cost for installing your new boiler.

Boiler Location

When looking at new boiler cost estimates online, it’s also worth considering where you live.

Typical labour rates for boiler install in central London could be as much as 2x that of the price of labour in the North. And that’s going to directly impact the quote you get for fitting a boiler.

Getting The Best Prices For Combi Boiler Replacement

There are plenty of ways to find great combi boiler deals.

However, there are some boiler installation providers that are better than others.

Personally, I’d always do one of two things before getting a new boiler installed.

Get a Quote Online

First, check out a fixed-price online boiler installer like Heatable. You’ll find top-rated system, regular, and combi boilers, like the Worcester Greenstar 4000 around £100-200 cheaper than a lot of other install companies will charge.

Boiler prices from Heatable

Have a Home Visit

If you’d prefer an on-site visit to spec your property, and then get up to 3 quotes from local installers, you can fill out this form and do that for free.

FAQs On Boiler Installation Costs

Below, we’ll address some common questions about replacement boiler costs, including installation.

What is the average cost of installing a new boiler? 

The typical cost of installing a new boiler is around £2,200. This figure is based on a mid-range combi boiler cost plus the labour involved in installation. It also accounts for the magnetic filter, limescale filter, and plume kit cost.

Keep in mind that the figure above is a very rough estimate. In today’s volatile economic and geopolitical climate, boiler price points can fluctuate wildly in response to the uncertainty.

What’s more, there is a range of more “stable” variables that ultimately affect how much you’ll pay. For example, a boiler manufacturer like Vaillant produces excellent boilers, but these tend to cost more than made by Viessmann, and equally great boiler brand.

The complexity of installation is yet another determining cost factor. A simple combi swap will cost far less than installing a completely different boiler system, or moving your appliance to a new location.

If you’d like to get accurate quotes for all your installation options, you can use Heatable’s anonymous online calculator to get a range of fixed-price quotes right here on your screen. Alternatively, you can contact local heating engineers and ask them for an estimate.

Are British Gas expensive for boiler installation? 

In most scenarios, established national companies like British Gas will charge more than a local heating engineer. You’ll also pay less when using an online installation company like Heatable.

Can I legally install my own boiler?

No, you cannot legally install your own gas boiler — not unless you’re Gas Safe registered. And if it’s an oil boiler you need to install, you’ll have to hire an OFTEC engineer to perform the work.

Can a plumber intall a boiler? 

Whilst a plumber can service plenty of other components of your heating and hot water system, they can’t legally install a boiler. That’s because plumbers lack Gas Safe training and registration, which is mandatory for performing any work on gas appliances like boilers.

Is it legal to service your own gas boiler?

The short answer is no — you can’t legally service your own gas boiler unless you have a Gas Safe registration.

The long answer is a bit more complex, but simply put, you can service those parts of the boiler that the manufacturer intends users to service. These typically include non-gas-carrying components.

If you’re not sure whether the work you’re about to perform is legal, it’s always best to call a Gas Safe engineer.

Are gas boilers being phased out? 

Gas boilers will likely be phased out from new homes starting in 2025. At the time of writing (editor’s note — February 28th, 2022), there are no plans to ban the public from installing new gas boilers in existing homes.

What is involved in changing to a combi boiler?

If you currently have a system or regular boiler setup, changing to a combi boiler will involve removing the hot water cylinder and possibly the water storage tanks.

Along with these water storage devices, you’ll also have to eliminate parts of the existing pipework that comprises your central heating system and reconfigure it to work with the new combination boiler.

Depending on the configuration of your existing central heating and hot water system, parts of your drywall may need to be removed and replaced, too.

What’s Next? Still Not Sure Whether to Replace Your Boiler?

Hopefully, our guide will help you make an informed decision before you get a new boiler replacement.

Got questions about the best boiler brands to buy, which boiler fitter to use, or whether your install quote is a rip-off? Fire away and leave a comment below; we’ll get back to you as soon as we can.


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