Gas heating has many advantages for modern homeowners. The fuel is fast and flexible and available from a continuous piped supply. It is clean in operation with no soot or residue, and the latest heaters have many features such as automatic ignition, variable heat settings and automatic flame failure safety devices. The gas supply shuts itself off automatically should the flame go out.
The three main uses for gas heating are as room heaters, space heaters and central heating systems.
The room heater is simply an appliance consisting of a radiant panel heated by a gas burner. Many new types also offer a combination of radiant and convected heat. Space heaters are large enough to warm two or three rooms. The unit is generally installed in a fireplace. Central heating heats the whole house if required. There are two main systems, one where the air is heated and distributed to the various rooms through ducting. The ducting is usually under the house but may sometimes be in the ceiling with discharge registers usually in the floor.

Choosing the right sized heater.
As a general rule, 5 B.T.U per cubic foot (length x breadth x height), of an area to be heated will be enough for comfort.

Gas regulations require that UNFLUED heaters do not have a rating beyond 7 B.T.U per cubic foot of room space. In calculating the maximum B.T.U s permit­ted for UNFLUED heaters, room or area size up to closable doors is considered. If the home design does not fit the 7 B.T.U rule and more heat is needed to boost beyond closable doors, a FLUED heater is a good alternative or you can install two UNFLUED units,

The B.T.U or British Thermal Unit is simply a measure of heater capacity. The metric official measure is the MJ or Mega joule although B.T.U will be around for a while. 1 MJ1 = 948 B.T.U.

Maintenance.
If you have problems with a gas heating system, there is very little an unqualified person can or should do to rectify matters. Instead, you should contact the Customer Service Department of your nearest Gas Authority. Only qualified tradesman are allowed by law to install any gas appliance.