There are three main forms of boilers: Combination, System and Open Vent.
Combination Boilers
Combination boilers (combi boilers) will be the most popular boiler that's fitted in the UK right now. Combination boilers are units that get rid of the need for a hot water tank, and so save space in the house as no airing cupboard is required and no space is adopted in the loft. Because the name suggests, combination boilers combine two functions - not only do they provide hot water to a property, they also become a central heating boilers. Combination boilers run 'on demand' which means they provide instant hot water when required.
Pros of combination boilers:
- Space saving.
- Saves money because there is no warm water tank which must be constantly heated to help keep the water hot.
- Water received through taps along with other outlets reaches mains pressure
- Less pipe work is required when installing so installation is normally quicker.
Cons of combination boilers:
- As the water supplied by combination boilers is 'on demand' at mains pressure, if several outlets are opened concurrently (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 usually runs at about 1 bar of pressure. System boilers need a water storage cylinder to store the warm water for the property, which is generally installed in an airing cupboard.
Pros of system boilers:
- Good for homes with more than one bathroom as the kind of boiler system can deliver hot water, at exactly the same pressure, to several 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 often linked to two tanks housed in the loft space of a property. https://tsboilerservicing.co.uk/ of these brilliant tanks is a small 'feed and expansion' tank which is used to supply water to the boiler and radiators, another is a larger cold water storage tank which gives the water required for an open vented hot water cylinder.
Pros of open vent boilers:
- Mainly used in properties where there are several outlets (taps etc.) which may be used at the same time.
- Relatively cheap to replace.
Cons of open vent boilers:
- Low water pressure.
- If the hot water cylinder empties you might have to wait a while for this to re-fill and then warm up.
- Takes up a lot of space in comparison to other boilers.
As you can plainly see there are pros and cons for each type of boiler, for anyone who is still unsure concerning which boiler will best work for you, most good boiler installers will advise according to the list below:
If you have a set or bungalow with no roof space - Combi Boiler.
If your premises 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 lots of people in your property requiring warm water on demand - Combi or System boiler with a warm water cylinder.
If your property is a loft conversion - Combi.
When purchasing boilers for installation at home, or in the workplace, it will always be advisable to contact an installer who has each of the relevant qualifications to complete the job accurately and safely. An established installer of boilers may also offer you the very best advice concerning which system will suit your requirements. Do not attempt to use a boiler system yourself unless you are fully qualified.