If you smell gas: leave first
Get everyone and pets out of the house immediately. Do not flip light switches, unplug appliances, use a phone indoors, light anything, or operate a garage door opener. Do not go looking for the source. From outside and well away from the building, call the gas utility emergency line or 911. Do not re-enter until emergency responders say it is safe.
Why natural gas smells the way it does
Natural gas is naturally odorless. Utilities add mercaptan, a sulfur compound, specifically so leaks are detectable — it is the rotten-egg or sulfur smell people describe. That means the smell is a safety feature working exactly as intended, and it should always be treated seriously rather than explained away.
Telling furnace smells apart
| Smell | Likely meaning | What to do |
|---|---|---|
| Rotten egg / sulfur, persistent | Possible natural gas leak | Leave immediately, call the utility or 911 from outside |
| Burning dust, first firing of the season | Dust burning off the heat exchanger | Normal; should fade within an hour or two |
| Burning dust that never goes away | Excess dust, dirty blower, or a filter issue | Replace the filter; schedule service if it persists |
| Hot metal or electrical / ozone smell | Overheating motor, wiring, or control component | Shut the furnace off and call |
| Musty or moldy when the blower runs | Moisture in ducts, dirty coil, or condensate issue | Schedule an inspection |
| Oily or acrid | Combustion problem or venting issue | Call; may indicate incomplete combustion |
Carbon monoxide is different — and odorless
You cannot smell carbon monoxide. It is produced by incomplete combustion and can enter living space through a cracked heat exchanger, a blocked flue, or a backdrafting appliance. Every home in Buffalo with gas appliances needs working CO alarms on every level and near sleeping areas, tested monthly and replaced at the end of their rated life.
If a CO alarm sounds
Get everyone outside into fresh air immediately and call 911. Do not attempt to find the source or ventilate the house first. Seek medical attention for anyone with headache, dizziness, nausea, or confusion. Have all gas appliances and venting professionally evaluated before the system is put back into service.
After the property is cleared
Once the utility or fire department has confirmed the home is safe, a furnace evaluation should cover gas connections and joints at the appliance, gas valve condition, burner and heat exchanger integrity, venting from the furnace to the termination, combustion air availability, and combustion quality measurement. That is the work that establishes why something smelled wrong in the first place.
Property cleared and ready for service? Call 716-412-2677 — 24/7 availability.
Call now for a free quote and service availability. Please have your 5-digit ZIP code ready.