Combi boilers

Combi boiler

Combi boilers explained - 1:15

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Combi, or combination boilers, are the UK’s most popular type of boiler.

They provide heat to your radiators, plus limitless hot water on demand by heating water directly from your mains supply.

This makes them an economical solution for many households, as they only heat the water you use.

There’s no need to store water, so you don’t need room in your loft for a cold water tank, or space for a hot water cylinder.

This often makes them great for smaller homes where space is limited.

If you’re using more than one tap at the same time, the flow of hot water can be reduced, meaning they’re not always suitable for bigger homes with several bathrooms.

If you think a combi boiler is the right option for you, book an appointment with one of our expert Heating Advisers who can assess your heating needs and give you a quote.

If you’re happy with our quote, they can arrange an installation date that’s convenient for you.

Visit our website to find out more about boilers.

Or take a look at our other videos to find out more.

Combi boilers explained

  • Combi boilers are the UK’s most popular type of boiler.
  • Hot water for your taps and central heating system is supplied directly from the boiler unit.
  • Ideal for smaller homes and homes with one bathroom.


  • Provides limitless hot water on demand.
  • Can be an economical option, as combi boilers only heat the water you use.
  • A great space-saving solution with no need for a separate cold water tank or hot water cylinder.
  • Installation may be quicker as there are fewer parts in a combi central heating system.


  • Depending on your mains water pressure, the flow of hot water could be reduced if you’re using more than one tap at the same time.
  • Water can sometimes take a few seconds to heat up.

More useful information

We have offers and discounts available for a limited time only.

Find out how much you could save with a new boiler.

We have a range of boilers to suit your home.

Worcester Bosch Group Vaillant Baxi

Reasons to choose British Gas

Fixed price quote

We guarantee a fixed price

When our Heating Advisors quotes a price, we guarantee it won’t increase even if there’s unexpected work to do.

Boiler cost calculator

No deposit

Pay monthly with no upfront deposit

We could help you spread the cost over 3-10 years or you could choose to pay in full if you’d prefer.

Payment options

Your home is left clean and safe

Your home is left clean and safe

Our Engineers leave your home neat and tidy and will arrange the safe disposal of all waste.

Step by step guide

Free aftercare

Aftercare included

This offer includes HomeCare 200™ which provides service and repair for your boiler, controls and central heating system for one year.

Latest offers

British Gas New Heating Limited is authorised and regulated by the Financial Conduct Authority for its consumer credit activities. Registered in England and Wales 6723244.

[1] Mon-Fri 7:30am-8pm, Sat 8am-6pm, Sun 8:30am-5pm. Limited service applies during public holidays.

* 91% recommendation rating is based on 1,463 customer responses collected between 09/12/2014 & 02/02/2015.

91% of customers recommend British Gas boiler installations*. See below for more detail on how they rate it. Reevoo

British Gas Boiler Installation Service reviews verified by Reevoo

4,756 reviews

Reviews from: Sort by:
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Scores 9.0 out of 10 based on 4756 reviews
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8 out of 10


Luton Homeowner
Heating advisor needs to be more diligent when doing the survey. The installation engine came across several issues that I think should of been flagged on the initial survey
Published on: 25 May 2015
10 out of 10


Lower Earley, READING, Berks. Homeowner
The Boiler-replacement went very well, from the booking of the Job to the Parts Delivery, finishing with the Rubbish Removal. The Contractor, who did the work, was excellent!
Published on: 25 May 2015
10 out of 10


The installation engineer was prompt, clean and installed the boiler with a minimum of fuss.
Published on: 25 May 2015
10 out of 10


It was done with great care. left very tidy .Matched bricks outside as had to make a new
hole for the duct. very pleased and happy with new boiler. Water a lot hotter. all old boil. er bits collected next day. thank you.
Published on: 25 May 2015
10 out of 10


Milton Keynes Homeowner
Engineer called to provide ETA and was on time. Did an excellent job - very tidy. Full explanation provided of all works carried out. Would recommend to anyone.
Published on: 25 May 2015
10 out of 10


Axminster Homeowner
The new boiler was installed and the old one removed within several hours. We were hardly aware of the job being done! Although we did notice that we had lots of hot water after suffering just cold for nearly 3 months!
0 of 1 people found this review helpful
Published on: 25 May 2015