Boiler Installation Prices Explained

Boiler Installation Prices Explained: What You’re Really Paying For

Seeking guidance on boiler installation costs and what’s included in the price?

Many homeowners are surprised to see how much the cost of new boiler installation can vary, sometimes by over £1,000 between installers.

So, what’s behind the price differences, and how can you tell if you’re getting good value for money? In this guide, we’ll break down the actual cost of a boiler installation, explain what’s included in the price, and help you understand what affects the total cost, from the type of boiler you choose to the complexity of the job.

If you’re just starting your research, you might also want to check out our complete guide to boiler installation for a full overview of boiler types, sizing (kW), installation extras like smart thermostats and filters, and what to expect on installation day.

As a quick overview, boiler installation prices in the UK typically range from £1,500 to £4,000, depending on the type of boiler, the installer, and any additional work required, such as upgrading pipework or relocating the boiler.

For an accurate, fixed-price quote, you can get an instant online boiler quote with WarmZilla in just 90 seconds – no hidden fees, no sales calls, and complete installation by a Gas Safe engineer.

Gas Safe boiler installation costs

One of the biggest factors affecting your boiler installation cost is the Gas Safe engineer who fits it. A qualified engineer ensures your new boiler is installed safely, efficiently, and in full compliance with UK regulations – which is why professional installation is never an area to cut corners on.

If you’re thinking about buying a boiler separately and finding someone to fit it, you may find that many engineers refuse to install a boiler they haven’t supplied themselves. This is because they can’t guarantee the quality of the product, any missing parts, or the validity of the manufacturer’s warranty. You’ll also need to pay extra for essential parts like flues, thermostats, and filters, which are often not included when you buy the boiler alone.

When you buy through WarmZilla, everything is taken care of for you – from the new boiler and all required parts to Gas Safe installation, system testing, and disposal of your old boiler. You’ll also receive a fixed price upfront, ensuring no hidden costs or surprises on installation day.

Every home is different, and the total cost of your boiler installation will depend on factors such as:

• The type of boiler being installed (combi, system, or regular).
• Whether it’s a like-for-like replacement or a full conversion.
• The complexity of the installation (e.g., relocating the boiler or upgrading the pipework).

You can get an instant fixed-price quote online with WarmZilla in just a few minutes – no phone calls, no personal details required. It’s the easiest way to see precisely what your new boiler and installation will cost, based on your home and heating needs.

Cost for a system cleanse

A basic system cleanse is included in every WarmZilla installation. A system cleanse means adding strong chemicals to your heating system to clear out any sludge (rust from radiators and general build-up of gunk).

A system cleanse isn’t that expensive to do during a boiler installation as you have a Gas Safe professional in attendance with access to your system and the process is fairly simple when you know what you’re doing.

We also add inhibitor at the end of your boiler installation to keep the system coated to reduce corrosion, limiting the amount of sludge that builds up.

The cost of the system flush chemicals and inhibitor is usually around £30.

A powerflush (or Magnacleanse) however is much more expensive, ranging from £300 – £600 depending on how many radiators you have in your property and taking up to half a day to complete. Unless you notice cold patches on your radiators (when they’re turned on), then the chances are you don’t need one.

In older heating systems the vigorousness (it’s definitely a word), can cause leaks in older pipes as joins have their solder worked loose. For this reason, WarmZilla, don’t offer powerflushing as a service.

Cost of a system filter

As part of the installation, we also include a system filter, which is fitted on the return pipe to your boiler. The filter uses magnets to gather any ‘sludge’ that has been produced in your system to keep it clean.

The filter we fit with a Worcester Bosch 12Ri is the Worcester Bosch mini filter. Don’t be fooled by the mini part, this filter is mighty and will ensure your boiler is kept safe from nasty sludge in your system.

A Worcester Bosch mini-filter retails for around £120.

Cost of a plume kit

A plume kit is designed to adapt the location of flue outlets that no longer meet regulations, for instance, ones that are at head height or too close to windows or neighbours’ properties.

If you are worried about whether you might need one, don’t. With the WarmZilla survey we ask the questions needed to know whether you need one or not. If you do, we’ll add one to your order.

A plume kit costs between £100-£150 depending on the boiler brand and the boiler it needs to connect to.

Cost of a flue

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!

To buy a flue separately you would be looking at spending £80 – £130, but with WarmZilla the price of the flue and any flue extension kits you might need is built-in.

Cost of wireless controls/smart thermostat

There is a wide range of smart thermostats, all with different functions and with different price tags available on the market.

We’ve reviewed some of the most popular wireless/smart thermostats on the market including the Hive Smart Thermostat, Google Nest Learning Thermostat, Honeywell T3R and the Salus RT310i.

Smart thermostats make your home heating more efficient and help to save money on your heating bills. In addition to saving you money, they are also more convenient, allowing you to control your home temperature from your phone, Alexa, or tablet.

With every boiler installation, WarmZilla includes a Honeywell T3R thermostat with all combi boilers and a Hive Active Heating Smart Thermostat with all system and heat only boilers. We offer more advanced smart thermostats like the Google Nest Learning Thermostat if you like your tech.

The Honeywell is available for around £70, while the Hive costs a little more at around £150.

Cost to move a boiler’s location

The cost to move your boiler can be 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.

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.

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.

Cost to upgrade 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 than your initial boiler quote.

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 your boiler being installed in most cases.

Ready to See How Much You Could Save on Your Boiler Installation?

Understanding boiler installation prices is one thing – but getting a personalised, fixed-price quote is where the real value lies. With WarmZilla’s quick online survey, you can get an accurate quote in under two minutes.

No phone calls. No sales visits. Just a straightforward price that includes your new boiler, Gas Safe installation, and warranty, all in one easy package.

Start your online boiler quote now and see how simple saving on your new boiler installation can be.