How to replace your boiler

Replacing your boiler could save you money on your energy bills by heating your home more efficiently. Here is everything you need to know about getting your boiler replaced.

Man fixing boiler

In this guide you'll find answers to questions including:

  • Why should I replace my boiler?

  • Will a new boiler save me money?

  • How much does it cost?

  • How do I choose a boiler?

Why should I replace my boiler?

If your boiler has stopped working properly or if you have high heating bills, you should consider getting a new boiler. Other reasons to consider upgrading include:

  • Your boiler is over 15 years old

  • The cost of repairing your boiler would be more than replacing it

  • Your boiler is not energy efficient

  • You’re selling your home and want to increase its value

Before plunging in, follow these three simple steps:

Will a new boiler save me money?

Yes, you could save over £200 a year* on your energy bills if you upgrade from an old boiler to a new energy efficient system.

*Based on Ofgem's estimates of typical household usage.

You also avoid the costs of emergency call outs and expensive repairs by upgrading to a new, more reliable boiler.

The Energy Saving Trust has more information about how much you could save on your energy bill with a new boiler.

How else can I save money?

You can also save money on your heating bill by switching your energy deal and making your home more energy efficient, including improving your hot water system.

Switching energy deal can save you hundreds of pounds a year, which in turn helps reduce your monthly outgoings. However, it’s not just price you should consider – here’s everything you need to know about choosing the right energy tariff.

How much does it cost?

The cost of installing a new boiler can range from £1,000 to more than £4,000.

The cost of a new boiler is made up of:

  • The price of the boiler

  • The cost of installation

  • The potential cost of chemicals, which are required to flush your heating system

Installation costs are typically higher than the price of a new boiler, so speak with a local engineer to get an idea of total cost before you part with any money.

Try to get quotes from at least three Gas Safe registered engineers to ensure you’re paying a fair price from a qualified installer. 

You may be able to save money by choosing an engineer affiliated to the company that supplies your boiler – they could have access to special deals to help bring the cost down.

Can I install a boiler myself?

No, only a Gas Safe registered engineer can install a boiler.

Can I get help paying for a new boiler?

Yes, you could be entitled to help with the cost of a new boiler:

  • Energy Companies Obligation (ECO)

If you’re on a low income, this government scheme lets you upgrade your old boiler for free. Your energy supplier may be able to tell you if you’re eligible, or visit the Ofgem website for more information.

  • Warranties and insurance

If your boiler is insured or still under warranty, you could claim for a replacement if it’s faulty. Most warranties last up to two years after your boiler has been installed, but extended guarantees could last up to seven years. Check your home insurance policy documents to see if boiler breakdown is covered.

You may also be able to trade in your old boiler with your new boiler installer for a cash lump sum. Speak to your energy company or local boiler engineer about scrappage schemes.

What is the boiler scrappage scheme?

It was a Government scheme that offered money back for replacing your old boiler with a new energy efficient one.

The scheme has now closed, but you can still get help from other grants and schemes.

Is there an alternative to replacing my boiler?

There are other ways to save money, like having your boiler serviced, insulating your home, replacing your thermostat, or switching energy supplier.

How to choose a boiler

This will depend on your budget and the size of your home, but there are a range of boiler types to choose from:

Boiler typeDescription
Combi boiler Provides heat and hot water without needing a separate water tank. Combi boilers are best suited to small homes because they take up little space and often have lower water pressure.
System boiler Also known as a ‘sealed system’, this has a boiler and a water cylinder that sits in an airing cupboard, but no water tank. It supplies hot water to plenty of taps, but your water may not be instantly hot and could run cold.
Conventional boiler Has both a water cylinder and a tank, so you’ll need to find room to store both. Like system boilers, hot water can run out so you will need to wait for it to reheat. They suit large households because they can supply hot water to many taps at the same time.

Rent a boiler

If you cannot afford the upfront cost of a boiler, you could lease one for a monthly fee.

Be warned, you will be tied into your contract for 12 years or more and the overall cost is likely to be far greater than the upfront cost of a new boiler.

Where can I find a registered installer?

You can look for registered installers in your area on the Gas Safe Register website.

Compare quotes from several installers to make sure you get the best deal, and look for companies that have been in business for several years and have positive customer reviews.

Get estimated costs from your installer before they start work, along with an idea of how much time the work will take.

Last updated: 10 November 2020