A boiler is responsible for heating hot water and whole homes. When troubleshooting your boiler, it is important to first take a look at its normal operation. There are a series of processes which happen inside your boiler every time it switches on.
As soon as your boiler fires up, it is burning fossil fuels. Most boilers use natural gas, although oil is also common. In older boilers, a pilot light is continuously burning and will light the main flame when required. In more modern boilers, the gas is only lit automatically when it is needed.
The energy is contained in the gas is extracted by burning it. There are a series of small tubes which carry water through the boiler, this is heated by the flame. The water will come out of the other side of your boiler hot which can then be pumped around your home by using electrical hot water pumps.
The hot water can then be used to heat your home or supply hot water. Valves in the heating system will control whether the hot water is directed towards the radiators or used for hot water. In some boilers a supply of hot water is stored in a hot water tank and in others the hot water is used immediately.