A question many ask is whether their gas heater will work in the event of a power outage, that is, do gas heaters run on gas alone, without the need for electricity? The answer to that depends on the type of gas heater you have as some contain a continuous pilot light, some electronic ignition.
The evolution of the gas heater
The first gas heater was launched in 1856 by British company Pettit and Smith, using a design based on the same concept as the bunsen burner. A flame heated the air around it and that hot air spread through convection, heating the room. Coal remained the preferred method of heating homes well into the 20th century, until efficiency was substantially improved by the introduction of a heat exchanger to recover heat from the gasses. Today, most gas heaters use electronic ignition to light the flame.
Pilot light-controlled gas heaters
The majority of gas heaters today are controlled by electronic ignition but some older models are still pilot light controlled. When you switch the heater on, a valve releases gas into the burner, which the pilot light then ignites. The interesting thing is that electricity is used to sense if the pilot light is lit or not but it doesn’t require an outside source of electricity. Instead, electricity is generated by a thermocouple, which it does directly from heat. One of the junctions of the thermocouple lies in the pilot light flame, creating electricity which runs to an electromagnetic valve, and this in turn keeps the gas flowing to the flame. If the pilot light blows out, the thermocouple cools, the electricity ceases, and the valve shuts, cutting off the gas for safety.
Electronic ignition-controlled gas heaters
Electronic ignitions eliminate the need for a continuous flame burning within your heater by controlling the gas ignition electronically in the form of an electronically controlled high voltage electrical spark, which ignites the gas flowing from the pipe. Many prefer this method of ignition as they feel a pilot light wastes energy by constantly burning gas and can sometimes be unreliable.
Sophisticated ducted gas central heating systems also use electricity to control the fan and monitor the heater, flame sensor and safety functions. For example, electricity allows you to control the zoning functions easily, to programme the heating to be switched on or off in different zones so that you are not unnecessarily heating unused rooms. This sort of use combines the energy efficiency and cost effectiveness of gas with the benefits of electronic controls for the best of both worlds.