If you have a strange smell coming from your furnace, your first question is probably whether you need to shut your furnace off or can continue to use it. Some furnace odors are a sign of very serious problems; others are a normal part of running a furnace. Some may have causes that you can fix yourself; others should only be repaired by a professional.
If you smell gas in your home, you have an emergency – you need to call your local fire department immediately. You also need to shut off your furnace and open your windows; if the smell does not dissipate, leave your home at once, taking the rest of your family and any pets with you.
The most common furnace smell is a dusty one. When a furnace isn't used for a long period of time – for example, during the summer months – it can become dusty, and that dust burns away when the furnace is started up again. So if you're noticing a dusty smell and you've just fired your furnace up for the first time, give it a few days to go away on its own.
If the dusty smell doesn't go away, you may still be able to fix the problem yourself. It's possible that your furnace filter has become clogged with dirt and dust. If your furnace has washable filters, pull your filter out and wash it with water and mild detergent; let it thoroughly dry before putting it back into the furnace. If your filters are not washable, you'll need to buy a replacement filter.
If replacing or cleaning the furnace filter doesn't cause the smell to go away, you'll need to call in a professional to determine what's wrong with your furnace.
Another common furnace smell is that of burning plastic, and the most common cause is the plastic insulation on wiring. This is a serious problem, and you should turn your furnace off if you have this sort of smell. Continuing to run your furnace with damaged wiring could lead to an electrical fire.
If you have small children, it's worth it to check your vents before calling a contractor, however. Another potential cause of the smell of burning plastic is a plastic toy that's been stuffed into a vent. If you find one, be sure to wait for it to cool completely before removing it. Then fire your furnace back up and see if the smell goes away.
If you can't figure out the problem or if you need help, contact a contractor like Universal Enterprises Inc.