Midlands Home Comfort • Gas Furnaces • First Heat of the Fall
First Time Running the Furnace This Fall? Normal Smells and Sounds vs Signs It Needs Repair
A dusty smell and a few clicks are part of most first runs. Here is how to spot the ones that mean your furnace needs a look.
Direct Answer
A light burning-dust smell is common the first time a gas furnace runs each fall, and it usually fades within a few hours. A click or two, a quiet whoosh, and some duct ticking are usual too. Call for furnace repair if the smell lingers or smells like hot plastic, or if you hear banging or grinding. A rotten-egg smell or a carbon monoxide alarm is different. Get everyone outside first.
AAA Heating & Air, LLC. serves homeowners across the South Carolina Midlands, including Columbia, West Columbia, Cayce, Lexington, Irmo, Chapin, and nearby communities.
The Night You Finally Switch to Heat
One evening in West Columbia or Irmo the porch finally gets cold, and somebody switches the thermostat from cool to heat. A few minutes later the house smells like an old toaster. There is a click, a whoosh from the closet, and a tick from the ceiling.
“Is that supposed to happen?” Usually, yes. Here is how to tell.
What Is Usually Normal on the First Run
A warm, dusty smell that fades. Dust settles all summer on the burners and the heat exchanger, the metal chamber that keeps the flame and its exhaust apart from the air you breathe. When they heat up, the dust burns off. Carrier, a major furnace maker, says that smell typically lasts from about 30 minutes to a few hours.
A few clicks at startup. A gas furnace lights in steps. A small fan may hum first, then a click or two as the igniter, the part that lights the gas, goes to work.
A quiet whoosh. That is the burners lighting. The main fan often starts a little later, once the air has warmed.
Ticking or light popping in the ducts. Metal ducts grow a little as they warm and shrink as they cool.
The key word is brief. Normal sounds stay quiet, and normal smells fade.
Signs It Needs a Repair Visit
Carrier puts it simply: furnaces should be relatively quiet. Call for a look if you notice:
- A burning smell that lasts beyond a few hours or gets stronger.
- A smell like hot plastic or electrical wiring. Turn the furnace off and have it inspected.
- Banging, grinding, or squealing, or a loud bang as the burners light.
- Clicking over and over with no flame and no heat.
- Short cycling, when the furnace starts and shuts off again and again. A clogged filter can cause it, or a dirty flame sensor, the small safety rod that shuts off the gas if it cannot detect a flame.
- Cool air at the vents after the furnace has run a while.
- A furnace that will not start, or keeps shutting off.
- A breaker that trips again after one reset.
Any of these is a reason to schedule a heating repair visit. If only one room stays chilly, see our guide to one room that never feels right.
Stop and Get Out: Gas Smell or CO Alarm
These two are not “wait and see.” The steps below come from the gas utility and federal safety agencies. Call AAA only after they say it is safe.
If you smell rotten eggs or sulfur
Natural gas is odorless on its own. A sulfur-based additive gives it that rotten-egg odor so you can notice it. A hissing, roaring, or blowing sound can also signal a leak. Dominion Energy South Carolina’s gas safety page says if you suspect a leak:
- Leave the area immediately, moving to an upwind location.
- Warn others to stay away.
- From a safe place, call 911, then your gas utility.
- Do not try to find the source of the leak.
- Do not try to turn natural gas valves on or off, and never try to repair or reduce the flow of gas.
- Do not use any light switch, electric switch, telephone, garage door opener, cell phone, or flashlight in the area. They can cause a spark.
- Do not smoke, use a lighter, or strike a match.
- Do not start or stop nearby vehicles, and do not try to put out flames.
- Do not return until Dominion Energy or emergency services tell you it is safe.
If your gas comes from a propane supplier or another utility, follow that company’s emergency steps.
If a carbon monoxide alarm sounds
Carbon monoxide (CO) is a poison gas you cannot see or smell. The U.S. Consumer Product Safety Commission says that when a CO alarm sounds:
- Never ignore it, and do not try to find the source.
- Move outside to fresh air immediately.
- Call your emergency services, fire department, or 911.
- Do a head count.
- Do not go back inside until emergency responders give you permission.
- If a malfunctioning appliance was the source, do not run it until trained personnel have serviced it.
The EPA lists CO poisoning symptoms as flu-like (without fever): headache, dizziness, nausea, weakness, shortness of breath, and confusion. Feel those symptoms and suspect CO? Get to fresh air immediately and seek medical attention.
24/7 Heating Help
No heat on a cold night, or the responders cleared your home and said the furnace needs service?
Call (803) 253-1551 for 24/7 heating help from AAA Heating & Air. For a gas smell, always leave and call 911 and your gas utility first. Daytime scheduling: (803) 889-0686.
Safe Checks You Can Make First
No gas smell and no alarm? Try these first.
- Thermostat. Set to Heat and above room temperature, with fresh batteries.
- Filter. If it looks gray or packed, swap in a new one of the same size.
- Vents and returns. Keep vents open and furniture off the return grilles, the larger grilles that pull air back to the furnace.
- Furnace switch and breaker. Make sure the light-style switch near the furnace is on, and check the breaker marked furnace or heat. We recommend resetting it once. If it trips again, call us.
- Front panel. Make sure the furnace door is on and seated.
Leave to a technician: the burner compartment, gas lines and valves, wiring, and cleaning the flame sensor or igniter.
Still Unsure? We Can Take a Look
If the smell has not faded or the checks did not help, call (803) 889-0686 or schedule a heating check. We will find the cause and tell you straight if it is just normal first-run behavior.
Related YouTube
The filter is the easiest check on the list. Here is our short tip.
Frequently Asked Questions
Why does my furnace smell like burning the first time I turn it on?
Usually it is dust burning off. If it lasts beyond a few hours or gets stronger, have it checked.
Is clicking normal when the furnace starts?
A click or two is common. Repeated clicking with no flame needs a repair visit.
What should I do if I smell rotten eggs?
Leave right away. From a safe place, call 911 and your gas utility.
My CO alarm went off. Can I just open a window?
No. CPSC says go outside immediately, call 911, and stay out until responders say otherwise.
When should I call AAA Heating & Air?
Call (803) 889-0686 when a smell lingers, a noise repeats, or the furnace short cycles.
Final Recommendation
A little dust smell is usually just your furnace waking up.
If something seems off, call (803) 889-0686. We would be glad to help your family stay warm through a Midlands winter.