Maria G.
2 weeks ago
Our AC quit on the hottest day of the week. They came out the same afternoon, explained exactly what failed, and had us cool again within two hours.
Different smells point to different causes. A musty smell usually means moisture or a dirty coil. A burning smell can mean an electrical problem. A gas smell is an emergency and means you should leave the home.
Tell us exactly what you smell and when. It helps us diagnose faster.
What You Notice
A musty or damp smell when the system starts
A burning or hot smell
A dirty sock smell from the vents
A rotten egg smell, which is a gas emergency
A sweet or chemical smell
Could Also Be
Signs It Is This
The smell appears when the system starts
It gets stronger when the system runs
It is worse in humid weather
You notice allergy symptoms at home
Is It Safe to Keep Running?
If you smell gas, leave the house right away and call your gas utility from outside. Do not use switches.
A burning plastic or electrical smell means turn the system off and call us.
What You Can Check Yourself
Replace a dirty air filter
Check for standing water near the indoor unit
Run the fan to dry the coil
Open windows if the smell is strong, unless it is gas
If the smell returns, have a technician check the coil and drain line.
Go Deeper
Why It Happens
Condensation collects on the indoor coil and drains away. If it does not drain, or if dust and moisture build up, bacteria and mold can grow and the smell travels through the ducts.
Parts Involved
Evaporator coil
Drain line and pan
Ductwork
Air filter
Electrical connections
Gas connections on furnaces
What a Technician Does
A technician inspects the coil, drain line, and ducts, finds the source, and recommends the simplest fix first.
When It Happens
Quick Facts
Likely cause
Dirty coils, a clogged drain line, mold, or an electrical issue
Also described as
Musty smell, burning smell, dirty sock smell from the vents
Urgency
Immediate for burning or gas smells, soon for musty smells
Most common when
At startup or after a long period of use
Typical fix time
1 to 2 hours for most causes
First thing to check
Note what the smell is like and when it happens.
How we fix it
Noticing this at home?
We will confirm what it is and treat it safely, with pet and kid friendly products explained first. The inspection is free.
Prefer to talk? Call us
(941) 000-0000
Honest diagnoses, no pressure
Friendly, professional service
Clear pricing before any work
Repairs backed by our warranty
What our customers are saying
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