A __________ is used to shut off the supply of gas to an appliance in an emergency.

The most common fuel used in domestic boilers in the UK is __________.

A __________ must always be fitted to prevent, Ingress, and backflow of POC.

Domestic fuel systems should be checked for __________ to prevent hazardous situations.

An appliance must be correctly __________ to ensure safe and efficient operation.

Gas appliances must be serviced annually for safety.

Oil-fired boilers do not require a flue.

Carbon monoxide detectors should be installed near sleeping areas.

Flexible hoses can be used for permanent gas connections.

Only a qualified engineer must carry out work on gas appliances.

Leaks in fuel systems can usually be detected by smell alone.

Incomplete combustion of fuel can produce the toxic gas

Natural gas is mainly composed of the chemical compound ________