What is a combi boiler?

By Jonathan Millard

A boiler is basically a water heater which can provide heating and hot water to your home. They burn gas or oil to heat your water, and are the conventional method of providing residential and commercial premises with heating and hot water in the UK. Combi boilers are one of three main types of boiler widely used by homes and businesses.

Combination boilers, or ‘combi boilers’, no matter which combi boiler you choose, it will always deliver hot water on demand, by taking cold water from the mains and heating it as needed. This way, hot water is available ‘on tap’, 24 hours a day.

What is a combi boiler good for?

Combi boilers are ideal water heater systems for small houses or flats. They are economical to run and don’t take up much space, as they don’t require an external hot water tank. They are also one of the most straightforward boilers for a Gas Safe engineer to install.

What is a combi boiler not so good for?

You won’t be able to use hot water from many sources at the same time, and this choice is not ideal if your property has low water pressure.

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Other types of boiler include system condensing boilers, which are better suited as water heater systems for larger homes with a need for more hot water. They have a sealed hot water storage cylinder which can be installed in a space such as an airing cupboard. Heat only boilers, or ‘open vent condensing boilers’, require two tanks in the loft and a hot water tank in an airing cupboard. These are best for those who need to replace a heat only boiler cheaply, and people who want to be able to run hot water from more than one tap simultaneously.

Older boilers

If your home has a very old central heating system then you may be wise to invest in a newer model, as this could save you up to 35% on your average yearly heating bill.

Small homes benefit from combi boilers for the reasons mentioned above, so it’s no surprise that they are the best-selling boiler type for gas central heating, accounting for around 70% of new boiler purchases. However, if this is your choice then you will also need to decide which combi boiler to install.

Which combi boiler should I choose?

If you have decided to install a combi boiler, you can call aspect.co.uk to discuss the options open to you regarding which combi boiler to opt for. There are a range of different types and brands which all work in the same way, acting as a water heater for cold water straight from the mains.

aspect.co.uk can give further information on ‘what is a combi boiler’ and guide you through the various considerations involved in choosing which combi boiler to install.

Our Central Heating and Hot Water Engineers

aspect.co.uk covers London and the surrounding areas, our team is over 100 strong and are familiar with all the major brands and models including: Baxi, Broag (Avanta), Glow Worm (Ultracom, Flexicom, Betacom), Ideal (Classic, ICOS, ISAR, ESPRIT, ELISE, Mexico), Keston (Qudos), Main, Potterton (Suprima, Promax, Performa, Gold), Vaillant (Ecotec), Worcester (Greenstar, Highflow) and Honeywell Controls. Meet a few of our heating and hot water experts in London:

  • London , Peter Lowry Peter Lowry in N16
  • London , Tomasz Kowalski Tomasz Kowalski in E17
  • London , Tomas Kerbelis Tomas Kerbelis in EC4
  • London , David Forbes David Forbes in SW14