FURNACE PROBLEM · DIAGNOSIS GUIDE
Some furnace smells are completely normal. Others are warnings you should not ignore. Here's how to tell the difference.
Sulfur / rotten-egg smell = gas leak — evacuate and call your gas utility's emergency line first. Strong burning rubber, plastic, or smoke = turn the system OFF immediately and call us. CO detector alarm = leave the house, call 911.
Dusty smell on first startup of the season. When the furnace runs for the first time in months, accumulated dust on the heat exchanger burns off. Smells like burning dust for 5-30 minutes, then clears. This is normal.
Faint metallic smell on a new furnace. The first few weeks of a new install can produce a slight metallic smell as the heat exchanger seasons. Should clear within a few uses.
Could be a blower motor overheating, melting wire insulation, or a foreign object that fell into the duct. Turn the system OFF and call us same-day.
Gas smells are emergencies. Get out of the house and call your gas utility's emergency line first, then us once you're safe.
Stop running the furnace. Could be cracked heat exchanger, electrical issue, or actual fire risk inside the unit. Call us immediately — 24/7 dispatch is available.
This is the additive in natural gas — it means you have a leak. Evacuate, call your gas utility's emergency line, then us once safe.
Any smell that's strong, lasts more than 30 minutes, or makes you uncomfortable should be diagnosed by a pro. Furnace issues that cause smells often involve heat exchangers and gas — not areas to DIY.
Call (973) 948-0680. 24/7 emergency dispatch with real licensed technicians.
“Burning plastic smell scared me. They walked me through what to look for over the phone — turned out a foreign object had fallen into the duct. Quick fix, very calm crew.”
Kelly J. · Andover, NJ
Same-day appointments in Sussex and Morris counties. 24/7 emergency dispatch — answered around the clock by a real on-call technician.
98 Morris Turnpike, Newton NJ · NJ HVACR Lic #19HC00108700 · Since 1999
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