Zed's Guide to Boilers
Natural Gas Boilers
The mains gas used in this country is called Natural Gas or Methane (CH4). Natural Gas is currently established as the popular fuel of choice for domestic central heating systems. Natural Gas is available via a main feed, meaning no on site storage is required. Although natural gas is the most popular fuel option in the UK, it may not be available to everyone. If this is the case, then another fuel option is required for you to run your central heating system. It is also a legal requirement that gas boiler installations must be carried out by a GAS SAFE REGISTERED engineer.
LPG (Liquid Propane Gas)
Liquid Petroleum Gas is most commonly referred to as LPG. LPG is an alternative option used for homes that aren’t connected to the mains gas feed, and although it works in the same way as Natural Gas, it is slightly more expensive to run. Unlike Natural Gas, LPG is actually stored on site in a cylinder or tank, which is then supplied via a pipeline into the property. The range of LPG Boilers are less than those available in Natural Gas, however some, Natural Gas boilers can be converted to LPG using the appropriate LPG Conversion Kit. It is also a legal requirement that all LPG Boiler installations are carried out by a CORGI Registered engineer.
Oil
Similar to LPG, Oil is an alternative option used for homes that aren’t connected to the mains gas feed. The Oil is stored in an oil storage tank (also available here at PlumbNation), and supplied via a pipeline direct from the tank to the property. A well installed oil fired heating system will give you every bit as much efficiency as a gas system. Oil can be more expensive to run than Natural Gas, however, with Oil central heating, you have to flexibility to switch oil suppliers if prices increase, thus keeping costs down. Oil produces higher carbon dioxide emissions than gas, so is a worse fuel to burn, therefore making it a less environmentally friendly. It is also a legal requirement that all Oil Boiler installations must be carried out by an OFTEC registered engineer.
Electric
As electricity is obviously widely available to every home, it can therefore be used to power your central heating boiler. Electric Boilers are actually 100% efficient to the end user since there is no heat loss. There is also no need for a flue, as there is no fuel to extract. Electric Boilers are compact, light and completely silent. Although the initial installation of Electric Boilers is fairly economical, the cost of running and Electric Boiler will cost considerably more on a day to day basis, as opposed to Natural Gas Boilers.
Combination Boilers
A Combi Boiler (or Combination Boiler), is generally considered to be the UK’s most popular type of boiler. It is a compact and highly efficient unit, giving all the heating and hot water you need with significant savings on running and installation costs.
Unlike a conventional heating and hot water system, a combi system does not store domestic hot water. It heats water directly from the cold mains, as you use it. There’s no requirement for a hot water cylinder, no tank in the loft (and so less risk of freezing and flooding) and none of the connecting pipe work. So you not only save space, but also reduce hot water costs – which can account for up to 60% of a typical domestic fuel bill.
A Combi Boiler also supplies hot water at mains pressure, giving you exhilarating power showering, without the need for a pump.
When choosing a combi boiler, it is important to establish the heat output and flow rate suitable for your requirements. If you require a higher flow rate, then there are combination boilers that are specifically designed to provide this. E.g. the Worcester Greenstar Highflow CDi Range and the Vaillant EcoTEC Plus 937 are particularly popular, offering as much as 25 Litres per minute.
Regular Boilers
Regular Boiler systems, otherwise known as “conventional boilers” are used in a more traditional central heating system. If you are looking to replace an old boiler, then this is possibly the system that you currently have.
A regular boiler works on the basis of “heat only” and therefore requires a separate hot water cylinder (usually located in an airing cupboard), which stores a large amount of the household cold water. There are also two feeder tanks, (usually located in the loft area). One of the tanks is for domestic hot water, which feeds through to the hot water storage cylinder. The second tank is required for the central heating. The mains cold water is fed through the expansion/header tank, to the central heating system, which is heated via the boiler. This can also be called an “open vent system”.
Having a regular boiler system, means that unlike a Combi Boiler system, the hot water flow rates tend to be higher as the hot water is already stored in the hot water cylinder. This allows the use of several hot water outlets being operated at the same time within the property.
Due to the number of components that a Regular Boiler system requires, this means that it uses up more space, than any other heating system.
PlumbNation offer a wide range of Regular boilers, from the UK’s most popular and quality assured manufacturers, such as Vaillant, Worcester and Baxi.
System Boilers
System Boilers work in the same context as the Conventional Boilers, where they indirectly heat a separate store of domestic hot water.
Although similar in many ways, the difference between a System boiler and a Conventional (Regular) Boiler, is the System Boiler incorporates all the major components built-in, including an expansion vessel and modulating pump. Generally all components are pre-wired, pre-plumbed and pre-tested for greater reliability, as well as a quicker and neater installation.
PlumbNation offer a wide range of System boilers, from the UK’s most popular and quality assured manufacturers, such as Worcester, Glow worm and Vaillant.
Storage Boilers
System Storage Boilers provide both central heating and plentiful supplies of hot water. This is achieved by combining a boiler and an unvented cylinder in one unit, with all the necessary controls. That also means a dry loft, for simplicity and peace of mind.
Naturally, these units are designed for fast and easy installation. Whilst space is freed up in the property due to their compact design, there is an added benefit of achieving mains pressure hot water from more than one outlet, simultaneously, even after the full contents have been used, hot water is still available instantaneously at a reduced rate.
PlumbNation offer a wide range of Storage boilers, from the UK’s most popular and quality assured manufacturers, such as Glow worm, Potterton and Ideal.
Commercial Boilers
When looking to heat a large domestic property or Commercial building then a standard domestic boiler probably wouldn't have the capacities to service such demand, this is when a commercial boiler is required. When heating a commercial property, now this could be a small cafe / Bar, sports centre, church or even a large office building to name but a few, then a commercial boiler has a range of heat outputs capable to achieve the demand.
A commercial boiler works pretty much as a regular (conventional) boiler does, in the sense that the boiler provides Low Temperature Hot Water (LTHW) to heat the radiators in a building whilst also capable of providing indirect hot water via a hot water cylinder. Most commercial boilers are mains fed, or otherwise known as sealed systems, where there will be a need for a pressurisation unit & expansion vessel to accomodate water expansion (of which PlumbNation can offer a full range of ancillaries to compliment our range of commercial boilers).
PlumbNation provide a full range of commercial boilers with a variety of options, including wall hung condensing (maximum efficiency) and floor standing conventional flue boilers from leading Industry manufacturers such as Ideal and Potterton.
Flues
A flue is a pipe or chimney that is used to extract the waste gases, from the combustion process in the boiler, to the outside of the property. The waste gases are mostly carbon dioxide and steam. This is sometimes extracted through the flue terminal as a “white plume or discharge”. This is due to the fact that as with all condensing boilers, the flue gases are exhausted at around 55°C and therefore cool quicker when entering the atmosphere and in certain temperatures, can create a plume, similar to a breath on a cold morning. It is this Plume or wastage that needs to be extracted correctly away from the property.
There are various different flueing options available, and it is recommended that you speak to your plumber or the manufacturer, who will be able to provide expert advice on your flueing requirements.
PlumbNation can provide you with all the necessary boiler accessories that you require for your installation.
SEDBUK Ratings – Energy Efficiency Bands
SEDBUK (Seasonal Efficiency of Domestic Boilers in the UK) is a method for calculating the efficiency of central heating boilers, which is developed and agreed with boiler manufacturers. Its purpose is to identify the efficiency rating of boilers in an A to G scale that is simple to understand and recognise. It enables a fair energy efficiency comparison between different boilers, which are scored and placed in a banding system, the most efficient being Band A. Boilers of a higher efficiency rating mean that the least fuel is wasted, making the boiler more environmentally friendly, and more cost effective.
The current legislation in England and Wales states, that from 1 April 2005, all Gas-fired boiler installations in new or existing properties, must be condensing boilers (rated SEDBUK Band A or B). The same legislation for Oil-fired Boilers was applied as from 1 April 2007.
A Condensing Boiler is more efficient due to its ability to extract more heat from the flue gases normally lost to the environment through the flue system. As the gases pass through the heat exchanger, this extra surface latent heat within, which would normally be lost to the atmosphere, is instead released and applied to the system. It is this ability to extract as much heat as possible from the gas it burns that gives the condensing boiler an exceptionally high level of operating efficiency.
PlumbNation offer a wide range of condensing SEDBUK Band A and Band B rated boilers so that all our customers benefit from having the highest rated efficiency boilers on the market today, and save money on fuel bills.
SEDBUK Rating Scale
BAND A: 90% - 91.3%
BAND B: 86% - 90%
BAND C: 82% - 86%
BAND D: 78% - 82%
BAND E: 74% - 78%
BAND F: 70% - 74%
BAND G: Below 70%
