While some newer gas furnaces have an electrical apparatus that ignites the gas, older ones typically have a pilot light that can be relit if it goes out.
Although the procedure may vary slightly by manufacturer, the following will give you a pretty good idea of how to relight a pilot yourself.
When relighting your furnace’s pilot, it’s probably a good idea to check the air filter as well. The filter removes dust and dirt from the air as it passes through your furnace. Your furnace is responsible for distributing air throughout the house in the winter and summer so it’s important to keep your filter clean. If you have pets you may want to consider changing the filter more often as hair can cause the filter to clog more quickly.
Your filter size and type can vary greatly by manufacturer but is easy to do yourself. Most manufacturers recommend changing your furnace filter every 30 to 60 days. One of the most common reasons we see for unnecessary service calls on furnaces is a failure to change the filter regularly.
You can expect your furnace and air conditioner to run smoothly for many years with proper maintenance. Your heating and cooling system should be serviced twice each year–in the spring and the fall–before they are exposed to their most rigorous use.