Blog>Cost Guides>How much does a boiler flue replacement cost?
Last updated: 12 September 2024
How much does a boiler flue replacement cost?
Your boiler flue is essential for allowing gases and condensation from your boiler to escape your home. Here’s how much a boiler flue replacement costs.
Fast Facts
The average cost to supply and install a straightforward horizontal boiler flue is £200
Costs are closer to £550 for more complex vertical flue installations
If you’re having a new boiler installed, the boiler flue replacement cost will often be included in your overall price
Your boiler flue is a large pipe that carries exhaust gases from your boiler to outside your home. So, it’s essential for keeping you and your family safe.
But what happens if your boiler flue becomes damaged, you need to relocate it or you’re planning to switch your existing boiler for a new one? Here, we’ll explore the average boiler flue replacement cost.
What does a boiler flue replacement cost?
The average boiler flue replacement cost is £200 for a straightforward horizontal boiler flue.
However, if your installation is more complex, your costs can start to climb.
| Item | Unit | Cost - low | Cost - high | Average cost |
|---|---|---|---|---|
| Straightforward horizontal flue installation | Per project (supply and installation) | £180 | £250 | £200 |
| Vertical flue installation | Per project (supply and installation) | £400 | £700 | £550 |
| Basic horizontal flue kit | Supply only | £70 | £130 | £100 |
| Vertical boiler flue kit | Supply only | £100 | £500 | £300 |
| Extension flue pipe/flue bends | Per m (supply and installation) | £75 | £125 | £100 |
| Last updated: September 2024 Our costs are ballpark averages - get a local tradesperson to quote now | ||||
To get a clearer idea of how much you can expect to pay for your boiler flue replacement, it’s best to get a bespoke quote from a Gas Safe registered engineer near you.
We always recommend getting at least three quotes to compare.
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How much does a boiler flue cost?
Most boiler flues in the UK are horizontal. These channel exhaust fumes straight through the external wall on which your boiler is installed.
You can expect to pay around£100 for a basic horizontal flue kit.
On the other hand, a vertical flue carries fumes from your boiler through the roof instead of your wall.
As such, they tend to be longer and often need extensions to be added to the pipework, leading to higher costs.
As a rough guide, a vertical flue kit could cost anywhere between £100 - £500.
How much does it cost to install a new boiler flue?
How much it costs to install a new boiler flue can vary depending on the amount of work required.
On average, your typical horizontal boiler flue will cost around £200 to install, including parts.
However, if the work is being done as part of a new boiler installation, this figure will often be included in your overall price for the project.
On the other hand, a vertical flue installation requires a lot more work and labour time, which can raise installation costs.
Exactly how much you can expect to pay will depend on the complexity of the installation and how far your flue stretches from your boiler.
That said, you’re looking at around £300 to construct six or so metres of flue pipe around several bends and through the roof. This figure also covers the cost of making good the brickwork where your old flue has been removed.
How much does a boiler flue extension cost?
If you’re moving your boiler somewhere other than an external wall, you’ll often need to add an extension pipe so your flue can reach a safe area outside.
Extending your boiler flue in this way typically costs around £75 - £125 per m.
This includes both supply and installation, as well as the cost of creating a new hole for the flue to exit your home.
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Factors affecting the cost of replacing a boiler flue
When estimating the cost of replacing a boiler flue, there are lots of different factors to consider.
Here are the main ones:
Whether it’s a horizontal or vertical flue
The length of the flue
The complexity of the installation
Whether an access tower or scaffolding is required
Whether other work is being carried out at the same time
If you’re having your flue replaced as part of a new boiler installation, the price of a standard horizontal flue will usually be included in your overall cost.
However, if you need a vertical flue and the installation is particularly complex, you may be charged a separate fee.
Is a boiler flue replacement worth the cost?
Absolutely!
Your boiler flue is an essential part of your boiler. In fact, it’s just as important as the boiler itself as it keeps your home safe from poisonous gases like carbon monoxide.
If you’re considering a boiler flue replacement, it’s likely down to one of three reasons:
1. Boiler repair
If everything goes as planned, your flue should last as long as your boiler.
But if your flue is faulty, it will need to be repaired or replaced quickly for the safety of everyone in your home.
Replacing the boiler flue is one of the most common boiler repair costs.
2. Boiler replacement
Similarly, you’ll need to replace your boiler flue if you get a new boiler.
This will normally be included in your overall price, so it won’t be a figure you have to worry about.
3. Moving a boiler
Lastly, moving your boiler to a new position in your home will require a new boiler flue.
Most boilers are located on an external wall. But if you want to move yours to an internal wall to save space, this is where your costs can quickly climb.
It may not be strictly necessary, but if it increases the usable space in your home, it’ll often be worth the cost!
Key takeaways
The average cost to supply and install a straightforward horizontal boiler flue is £200
Costs can increase if you need a more complex vertical flue installation
You’ll need a boiler flue replacement if yours is faulty, if you’re getting a new boiler or if you’re moving your boiler to a new location in your home
Always make sure to hire a registered Gas Safe registered engineer
See the tradespeople we've checked and recommend for your job
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