Two types of oil are used for domestic heating:

• Kerosene heating oil Also known as 28-second or heating oil. It's the most common type used in UK homes and lighter and cleaner than gas heating oil.

• Gas heating oil Also known as 35-second oil or red diesel. It's usually used in older boilers, agriculture or commercially. 

​Oil-fired boilers use two different firing methods:

1. pressure jets or atomising burners
2. vapourising burners.

Pressure jet burners

Pressure jet burners use an oil burner that mixes air and fuel. An electric motor drives a fuel pump and an air fan.

The fuel pump forces the fuel through a fine nozzle, breaking the oil down into an oil mist.

This is then mixed with air from the fan and ignited by a spark electrode

​Vapourising burners

Vapourising burners work on gravity oil feed.
There is no pump. The oil flows to the burner, where a small oil heater warms the oil until vapour is given off and it is the vapour that is then ignited by a small electrode.

​As the vapourising burner is gravity fed, the main storage tank must always be higher than the burner, meaning less siting positions for the boiler itself.

​One of the issues with oil systems is purging air from the feed line.

​Test yourselves