High Urgency
Bad Smell From Vents
Musty, burning, or rotten egg smells coming from your HVAC vents. Different smells indicate different problems — some are urgent safety concerns.
What Could Be Wrong
01
Mold or mildew in the ductwork or evaporator coil
02
Dust burning off the heat exchanger (first use of season)
03
Dead rodent or debris in the ductwork
04
Gas leak (rotten egg smell) — evacuate and call gas company immediately
Typical Repairs & Costs
Duct cleaning and sanitization
$300 – $700
estimated range
Evaporator coil cleaning
$150 – $400
estimated range
Air filter replacement
$20 – $80
estimated range
Costs vary by ZIP code. Check your local pricing →
DIY or Call a Pro?
🔩 Call a Pro
This should be handled by a licensed HVAC technician. Attempting DIY could void warranties or create safety hazards.
Related Symptoms
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