What Are the Several types of Boilers Available?

What Are the Several types of Boilers Available?

There are three main forms of boilers: Combination, System and Open Vent.

Combination Boilers

Combination boilers (combi boilers) are the most popular boiler that's fitted in the united kingdom right now. Combination boilers are units that get rid of the need for a warm water tank, and so save space in the house as no airing cupboard is required and no space is adopted in the loft. As the name suggests, combination boilers combine two functions - not merely do they provide hot water to a property, they also become a central heating boilers. Combination boilers run 'on demand' this means they provide instant warm water when required.

Pros of combination boilers:

- Space saving.
- Saves money since there is no warm water tank which needs to be constantly heated to help keep the water hot.
- Water received through taps and other outlets is at mains pressure
- Less pipe work is required when installing so installation is generally quicker.

Cons of combination boilers:

- As the water supplied by combination boilers is 'on demand' at mains pressure, if several outlets are opened simultaneously (taps/showers/washing machines) the pressure can be reduced depending on how powerful the boiler is.

System Boilers

System boilers (sealed system boilers) comprise of a sealed unit that always runs at about 1 bar of pressure. System boilers require a water storage cylinder to store the warm water for the property, which is generally installed within an airing cupboard.

Pros of system boilers:

- Good for homes with an increase of than one bathroom because the kind of boiler system can deliver hot water, at exactly the same pressure, to many outlets simultaneously.
- No need for an expansion tank in the loft thus giving you more space for storage in the attic.
- High water pressure.

Cons of system boilers:

- Can be expensive to correct and install.
- Airing cupboard is necessary.

Open Vent Boilers

Open vent boilers are usually connected to two tanks housed in the loft space of a property. One of these tanks is a small 'feed and expansion' tank that is used to supply water to the boiler and radiators, the other is a larger cold water storage tank which provides the water required for an open vented hot water cylinder.

Pros of open vent boilers:

- Mainly utilized in properties where there are many outlets (taps etc.) which may be used concurrently.
- Relatively cheap to replace.

Cons of open vent boilers:

- Low water pressure.
- If  https://www.ljbheatingandplumbing.co.uk/  empties you might have to wait a while for it to re-fill and warm up.
- Takes up a lot of space compared to other boilers.

As you can see there are pros and cons for each type of boiler, for anyone who is still unsure as to which boiler will best work for you, most good boiler installers will advise according to the list below:

If you have a flat or bungalow without roof space - Combi Boiler.
If your property has 2 or even more bathrooms - System or Open Vented.


If you are within an area with low mains water pressure - System or Open Vented.
If you are looking to upgrade a preexisting conventional boiler to high efficiency - System, Open vented or Combi.
If there are many people in your premises requiring warm water on demand - Combi or System boiler with a hot water cylinder.
If your property is really a loft conversion - Combi.

When purchasing boilers for installation in the home, or at work, it is always advisable to contact an installer who has each of the relevant qualifications to complete the job accurately and safely. An established installer of boilers will also offer you the best advice as to which system will suit the needs you have. Do not attempt to install a boiler system yourself unless you are fully qualified.