Turn the gas control to pilot and hold it in while you light the flame with a match or a lighter.
Wall gas furnace pilot light.
When the thermostat signals for gas to be delivered from the gas valve to the burner it is the standing pilot that ignites the gas flowing to the burners to heat the air in the combustion chamber.
The pilot light in your gas furnace supplies heat to your home.
If the pilot light will not stay lit it needs to be fixed asap to supply heat to your home and for safety reasons.
A pilot light is a small continuously burning flame that is used to ignite the burners in older gas furnaces.
A number of reasons can cause the wall furnace to not light including a damaged thermocouple a.
If your old gas furnace has a standing pilot you can follow a standard procedure to relight the pilot light.
Keep the knob in for 20 seconds and then release it and turn it to the on position.
The flame is monitored by something called a thermocouple that is designed to shut off the gas valve to the pilot light in the event that it extinguishes or burns inefficiently.