Combination Boilers

Friday, 17th November 2023

A combi boiler is an increasingly popular choice not least because of its space saving qualities. In fact, combis now account for well over half of all the new domestic boilers installed in Britain every year. Compact size and hot water on demand makes combi boilers most suited to properties with limited space, or for couples or small families. Oil-fired combi boilers are available, however, gas and LPG models are more common.

A combi boiler is an efficient water heater as well as a central heating boiler and comes in a single compact unit.  They work directly from your mains water supply, so a hot-water storage cylinder or a cold-water storage tank is not necessary and therefore more space is freed up for other uses.

Another combi boiler benefit is that it can generally save you money on installation time and costs, since no tank in the roof space means less pipe work and a shorter installation time.  Hot water is delivered through your taps or shower at mains pressure, so you should enjoy a powerful shower without the need for a separate pump.

  1. Ideal for smaller properties because of its compact size
  2. No need for loft or storage space
  3. Quicker and easier to install
  4. Tidier installation since less pipework
  5. Cheaper option since no need for water storage cylinder
  6. Compatible with solar water heating systems.
  7. Combi boiler systems do not tend to suffer from air locks or low pressure, as the hot water is taken directly from the water mains.
  8. Combi boilers tend to be more efficient than other boiler types – a selling point when renting or selling a property.

  1. With a combi boiler it is not possible to run more than one shower or bath at a time, or to turn on the hot tap while showering. This may be an issue if you have several bathrooms and en suites in any one property.
  2. A regular boiler may be the best option for replacing an existing boiler if the property has an older radiator system. It might not be able to cope with the higher water pressure that is delivered by combi boilers.
  3. You might not have a power shower with a combi boiler, as the water pressure is set by the pressure level at the water mains.
  4. To ensure that a combi boiler is right for you, you need good mains pressure for it to work properly. Check what the mains pressure in your area is before you go ahead with the installation of your boiler.
  5. If a combi boiler breaks down, you may be left without hot water as well as central heating as there is no separate water tank.

As with any new installation, it is essential that any existing pipework and radiators are as clean and dirt-free as possible, otherwise they could cause damage to your new boiler, whichever type you choose.