Boiler Installation Guide

Need a new boiler?

In this guide, we'll explore everything you need to know about new boiler installation costs, what's involved in fitting a boiler, how long it takes, and whether it's DIY-friendly.

We'll also discuss how a boiler is maintained, and what you should consider when hiring a boiler specialist.

Let's get into it.

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What is Boiler Installation?

Boiler installation involves connecting a boiler to your home's central heating and hot water system.

A boiler provides heat for your home's radiators and supplies hot water for taps and showers.

Depending on the type of boiler, it may be connected to your home's hot or cold water storage tanks.

Types of Boiler

There are several types of boiler found in UK homes - let's take a closer look:

Combi Boiler

A combi - or combination boiler - makes use of a single compact central heating boiler unit and water heater.

Since combi boilers heat the water straight from the mains, a water storage tank is not required.

It costs around £1,200 to £4,000 to have a combi boiler installed.

Pros

• ✔ Relatively inexpensive to install
• ✔ Highly efficient, and heats up water quickly

Cons

• ✖ Not compatible with power showers or immersion heaters
• ✖ Pressure can be limited if multiple taps are used at the same time

System Boiler

A system boiler heats water for your home's central heating and hot water cylinder.

There's no need for a separate cold water tank, just the boiler itself and a hot water cylinder.

To have a system boiler installed, it will cost around £1,750 to £4,500.

Pros

• ✔ No cold water tank required
• ✔ Easy to install compared to heat-only boilers

Cons

• ✖ Needs more room than a combi boiler
• ✖ Hot water isn't instant

Heat Only Boiler

A regular, heat-only boiler - also known as a conventional boiler - needs a hot water cylinder and a cold water tank.

With a heat-only boiler, it's possible to get hot water regardless of the water's pressure in the mains. You can have hot water for multiple sources simultaneously with this type of boiler, too, making it suitable for large households.

It costs around £1,100 to £3,400 to install a heat-only boiler.

Pros

• ✔ Provides hot water, even with low mains pressure
• ✔ Suitable for large households

Cons

• ✖ Lots of space needed for a tank and cylinder, as well as the boiler
• ✖ Can be less efficient than other boilers

Electric Boiler

An electric boiler uses electricity instead of gas or oil to run.

Electric boilers are typically small and compact, quiet in operation, and easy to maintain - but their running costs are typically higher than gas.

It costs £1,700 to £2,900 to install an electric boiler.

Pros

• ✔ Easy to install
• ✔ Compact, no external flue required

Cons

• ✖ Running costs are higher than gas
• ✖ Not cost-efficient for large households

Oil Boiler

Oil boilers require an external tank, filled with oil, which is burned to provide hot water and central heating.

If you can't access a gas connection or live in a rural, off-grid location, oil boilers can provide a good heating alternative.

Oil boilers cost £2,450 to install.

Pros

• ✔ Useful heating solution for off-grid homes
• ✔ Good efficiency for large households

Cons

• ✖ Needs an external storage tank
• ✖ Higher running costs than gas

Biomass Boiler

Biomass boilers work by burning wood pellets, logs, or chips.

They're a renewable heating option, and are useful for off-grid homes.

Biomass boiler installation costs £13,200.

Pros

• ✔ Renewable energy
• ✔ Reduces reliance on fossil fuels

Cons

• ✖ Much higher installation cost compared to other boiler types
• ✖ Requires fuel storage

Why Should I Install a New Boiler?

Improved Efficiency

One of the advantages of fitting a new boiler is that it will offer significantly improved efficiency over what you're currently getting, especially if you have an old boiler.

As a general rule of thumb, the newer the model, the better the result.

Technical Upgrades

Many modern boilers allow multi-zone heating, advanced scheduling, and compatibility with smart home integrations, giving you better control over your home's heating.

Changing Boiler Type

You may wish to change boiler type to improve efficiency, save on money, or lower your carbon footprint.

How Much Does It Cost to Install a Boiler?

The average cost to install a new boiler is around £2,400.

Depending on the type of boiler and the complexity of the installation, this figure can change.

Who Can Install a Boiler?

Boiler installation is not a DIY job.

Depending on your boiler's fuel type, you'll need different contractors to install it:

• Gas boilers - Only Gas Safe registered engineers can legally install gas boilers in the UK.
• Electric boilers - Qualified electricians with NICEIC registration.
• Oil boilers - OFTEC registered heating engineers.
• Biomass boilers - HETAS registered heating engineers.

How Long Does It Take to Install a New Boiler?

A boiler installation typically takes 1 day.

If you're having a new fuel type installed, this timeline will be increased and will depend on factors like ease of access, coordination between energy suppliers, and the complexity of the installation itself.

Building Regulations or Planning Permission Approval for Boiler Installation

New boiler installations need to meet building regulations in the UK.

Planning permission is usually not required for boiler installations, as long as:

• Flues on the side or rear elevation of a property are not more than 1 metre higher than the tallest section of the roof.
• You don't live in a listed building, a conservation area, or an Area of Outstanding Natural Beauty (AONB).

Planning permission approval usually costs between £200 and £450, while building regulations approval and inspection tend to cost around £100 to £400.

How to Maintain a Boiler

Here are some ways to keep your boiler healthy over the years:

• Book an annual boiler service
• Run the heating regularly
• Bleed your radiators once a year
• Keep an eye on your boiler pressure, and top it up if needed
• Protect the condensation pipe from freezing in extreme temperatures
• Ensure a carbon monoxide alarm is fitted near your boiler
• Hire professionals if you have any concerns

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Questions to Ask When Hiring a Boiler Specialist

Before you settle on a heating engineer to hire, make sure you bear the following in mind:

• Make sure your contractor is qualified/certified for your boiler's fuel type (e.g., gas boilers need Gas Safe registered engineers).
• Find out if the contractor has public liability insurance.
• Ask if there are any guarantees or warranties on the labour and parts.
• Check if waste disposal (e.g., of the old boiler) is included, or charged as an extra.

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