There are three main forms of boilers: Combination, System and Open Vent.
Combination Boilers
Combination boilers (combi boilers) are the most popular boiler that is fitted in the united kingdom right now. Combination boilers are units that get rid of the need for a warm water tank, therefore save space in the house as no airing cupboard is required no space is taken up in the loft. As the name suggests, combination boilers combine two functions - not merely do they provide warm water to a property, in addition they become a central heating boilers. Combination boilers run 'on demand' which means they provide instant warm water when required.
Pros of combination boilers:
- Space saving.
- Saves money because there is no hot water tank which should be constantly heated to keep the water hot.
- Water received through taps along with other outlets reaches mains pressure
- Less pipe work is necessary when installing so installation is normally quicker.
Cons of combination boilers:
- As the water given by combination boilers is 'on demand' at mains pressure, if several outlets are opened as well (taps/showers/washing machines) the pressure could 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 hot water for the property, which is generally installed in an airing cupboard.
Pros of system boilers:
- Good for homes with an increase of than one bathroom because the type of boiler system can deliver hot water, at 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, another is a larger cool water storage tank which provides the water necessary for an open vented warm water cylinder.
Pros of open vent boilers:
- Mainly used in properties where there are many outlets (taps etc.) that may be used at the same time.
- Relatively inexpensive to replace.
Cons of open vent boilers:
- Low water pressure.
- If Helpful hints empties you may have to wait some time for this to re-fill and then warm up.
- Takes up many space in comparison to other boilers.
As you can plainly see there are benefits and drawbacks for each kind of boiler, for anyone who is still unsure concerning which boiler will best suit your needs, most good boiler installers will advise as per the list below:
If you have a flat or bungalow with no roof space - Combi Boiler.
If your property has 2 or even more bathrooms - System or Open Vented.
If you are in an area with low mains water pressure - System or Open Vented.
If you are seeking to upgrade a preexisting conventional boiler to high efficiency - System, Open vented or Combi.
If there are many people in your premises requiring hot water on demand - Combi or System boiler with a warm 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 all of the relevant qualifications to complete the job accurately and safely. A reputable installer of boilers may also offer you the best advice as to which system will suit the needs you have. Do not attempt to use a boiler system yourself unless you are fully qualified.