Smells From Your Vents: Causes and Fixes
Odors from your vents are worth taking seriously. Some are nuisances, and some are safety concerns.
Common causes
Musty or damp smell
Moisture and microbial growth on coils, in drains or in ducts.
Burning smell
Overheating electrical parts or debris. Turn the system off.
Dusty smell at first start of season
Often normal and brief.
Sewer-like smell
May relate to drain lines or plumbing and should be investigated.
Rotten egg smell
This can indicate a gas leak. Leave the building and call the gas utility or 911.
What you can safely check
- Replace the filter.
- Check for standing water near the indoor unit.
- Turn the system off for burning smells.
When to call a professional. For burning smells, turn the system off and call a technician. For a suspected gas leak, leave the building and call 911. Never open electrical panels or remove access covers on equipment. If you smell burning or see smoke, turn off power and call 911 if there is any danger.
Why does my AC smell musty?
Humidity and moisture buildup are common causes in coastal homes.
Is a burning smell serious?
Yes. Turn the system off and call us.
Can air purifiers remove smells?
They can help, but the source should be fixed.
Next steps and related help
Comfortable again, without the runaround
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