Central heating is the most common form of heating in the UK, and with energy prices rising, it is essential to have an efficient heating system. If you are having central heating installed or considering upgrading your existing system, it’s important to understand how the system works.
A full central heating installation could cost up to £5,000; this is a significant investment and the system will be expected to last for several years. It makes sense to understand how to install central heating, to ensure you select the right products to design an energy efficient system.
Most central heating boilers are combination or condensing boilers. If you have an older boiler it is recommended that you upgrade to a newer, more efficient condensing boiler. Both can be used with most fuel types, and it has been a minimum requirement of building regulations that condensing boilers are used with gas installations since 2005 and with oil installations since 2007.
Condensing boilers have larger heat exchangers than conventional boilers, and can draw more heat from the burning of the fuel. Some of the water produced during the combustion process condenses, and energy is also extracted from the vapour to produce more heat. This makes the boilers much more efficient, but does mean there is a constant drip of water which has to be taken out to drain.
As well as providing the central heating, the hot water in the house is heated via a coil of pipe which runs through the hot water cylinder. Combination boilers differ because they heat the water directly as it comes into the property, meaning they require no storage tank.
Radiators should be sized to each room to make sure they provide sufficient heat at all times of year. The sizing takes into account the room position, the size of the windows, the heat loss through the walls, the desired temperature of the room, the type of floor, and several other factors.
Your installer should be able to calculate the correct size for each room, and you can help by informing him if you have any special temperature requirements for a room. Consult with your installer over your choice of radiator design; he can source the various sizes and make sure they are available. It may be that you need to use two or three smaller radiators rather than one large one.
If you do use more than one radiator in a room, make sure they are installed at equal height; it will look better. Also consider the placement of furniture when you decide where to put the radiators.
Traditionally they were placed under windows, to heat draughts coming in; but since double glazing provides much better draught exclusion, radiators can be placed anywhere in the room. Obvious positions to avoid are behind a sofa or a large unit, as they will prevent the heat getting out into the room.
The heating and hot water are controlled by a single programmer, which allows you to preset two on and off times for each during the day. Most also allow you to set different times for weekdays and weekends. A thermostat is attached to the hot water cylinder which controls the temperature of the water and calls for heat as and when necessary.
A room thermostat, usually in a hallway or lounge, monitors the temperature of the house and controls the central heating. If you have a very large property you can use more than one room thermostat, and have the system designed so that you can isolate certain floors or areas, and only heat the parts of the house you are using.
Thermostatic radiator valves are put on all but one radiator in the house; the one left provides a bypass in case all the radiator valves are closed but the boiler is still on. Each valve can be set from one to six to control the temperature in each individual room. Once the set point is reached, it will close the valve and isolate the radiator from the system. This affords a greater level of flexibility and comfort, and also helps you to be more energy efficient.
The pipe work
Building regulations state that any pipe work within a metre of the boiler must be copper, but it is far more common for installers to use plastic for all the other pipe work. It is much quicker to install than copper so will save on labour costs, but it doesn’t look particularly good, so you may want to ask for any exposed pipe work to be copper.
Anyone is able to design a central heating system and carry out the majority of the installation, but a gas safe registered technician must make the connection to the mains gas supply. Making the connection also includes safety checks on the boiler, the pipe work supplying the gas, the location of the boiler, and the external flue.
Finding an installer
You should get at least three quotes from installers in the local area, and check their customer references and past history. You can contact the energy saving trust advice line on 0800 512 012 to find registered companies in your area; and you can also check the websites below for lists of registered installers:
The installation of central heating or the upgrade of a boiler will make your home much more energy efficient, and could save several hundreds of pounds per year on heating bills. It is important to understand how the central heating system works, and to have a rough idea of what sort of demand your lifestyle will place on it.
If you have a large family and use a lot of hot water for example, the system will need to be designed to cope. Consult your installer with your requirements and choice of boiler and radiators and be prepared to be flexible with your plans; this will allow him to design and install a system which will provide adequate heat and hot water for your home.