A controlled burn of fossil fuels, like gas or oil, takes place within the boiler and the heat produced is transferred to water.
The boiler consists of various components which transfer the heat energy from fuel to a heating system.
A heating system consists of:
* A boiler (the heat source)
* A cylinder (to store the hot water for system and heat only boilers)
* A pump (to push water around the system)
* A timer (to turn the hot water and heating system on automatically)
* Room thermostat (to control the temperature of the house)
* Cylinder thermostat (to control the hot water temperature)
* Radiators (to heat the room)
There are different types of boiler:
* Combination (or combi) boilers - heat water instantaneously on opening a hot tap, so there is no need for a storage cylinder.
* System boilers - these are designed to generate heat for your home as well as hot water that can be stored in a separate hot water storage cylinder. This can be situated anywhere in your home with no need for a separate tank in the loft.
* Heat only boilers - work in conjunction with a hot water storage cylinder and cold water top up tanks to provide both central heating and hot water.
The type of boiler you need will depend on a number of factors, such as the size of your house and your hot water requirements.
