Your furnace is the only appliance that keeps your home comfortable throughout the fall and winter, but just like any other large and complex system, it can suffer from a number of issues over the course of its normal operation. One of the most common issues that your central heating system may experience is the smell of burning when in operation. This can point to a number of different things affecting your furnace: understanding what some of the most common sources of the smell are can help you determine what you should do to get your furnace working properly again.
One of the most common reasons why your furnace may give off the smell of burning when you turn it on, especially earlier in the season when your unit has not seen a whole lot of use over the past few months, is because of an excessive amount of dust buildup within your ductwork. This is perfectly normal, and should go away within a few days, so if you can grin and bear it, you'll be fine. However, if the smell does not go away, or seems to get worse, the issue could lie with the interior of your heating system: replacing the air filter and cleaning out the ductwork may be necessary, so you should have a professional come in and inspect your unit.
Blocked Air Flow
Another common reason why your furnace may give off a burning smell is because individual vents are blocked. This is especially true if you notice that the smell of burning only occurs in one room or area of your home. Sometimes, this can be because something fell into your ductwork, like a toy or piece of food. Other times, it's because the vent itself is blocked by furniture, carpeting, or some other installation within your home. Opening up the vent and removing the blockage will get rid of the problem in the first case, while rearranging your furniture will accomplish the same in the second.
Finally, if the above two points are not the contributing reasons to the burning smell that your furnace is producing, the issue may be an electrical one. Older or improperly installed wiring and electrical work can cause the smell of burning, as can mechanical issues within your furnace yourself – such as a burned-out motor or fan. In either case, you'll have to have a professional HVAC services contractor look at your unit to pinpoint where, exactly, the smell is coming from, and what should be done to fix it.