Smelly Odors That Warn Of Signs Of AC Repair Problems

Before highly contagious microbes entered our living and working spaces, building occupants were on heightened alert for sick building syndrome. Today, a strange odor emanating from the air conditioning system can result in a dozen calls to the building manager. 

Many early signs of AC problems can be diagnosed from odors. Here's a short guide to air conditioner smells to help you decide if you need an AC repair, cleaning, or tune-up. 

AC Repairs for Odor Control

Rubber to the road

When a fan belt or motor wears down in the blower fan, the rubber parts can create the smell of burning rubber. Very similar to the smell from a broken fan belt in your car. Your AC needs this basic component to blow air. An AC repair technician will fix the belt and put your aircon unit back in operation. 

Smoking guns

Circuit boards with smart chips more efficiently manage the use of energy in an air conditioner. When a circuit is shorted, you may notice a burning smell, often compared to the smell of gunpowder. Like in your computer, if the brains of your AC unit don't work, the unit will not function. An AC repair person will fix or replace the circuit board to put your AC back in normal operation. 

Rotten eggs

Gas leaks can be deadly and should hasten immediate repair. The smell of sulfur is a sign of a gas leak in your home. While the nauseating odor of exhaust fumes is associated with refrigerant leaks from the AC unit. When the AC coils that circulate cooling fluids are damaged, refrigerant seeps out. 

AC Cleaning & Tune-Ups for Odor Prevention 

Stinky socks 

If a moldy, musty smell is wafting through the air, your air conditioner may have the dreaded dirty sock syndrome. The smell of stinky feet is a buildup of mold and bacteria on the AC coils. Some basic AC maintenance can eliminate the smell by cleaning or replacing the evaporator coils. 


The mold and mildew grow when there's too much moisture in your AC unit. You can prevent toxic buildups and more serious damage by having AC technicians perform regular AC cleaning and filter changes. 

Many odor-causing AC repair problems can be traced back to improper air conditioning installation. Refrigerant levels, circuit board placement, or AC unit size that do not meet the manufacturer's standards can lead to damage. These problems can be avoided by using an AC installation technician who specializes in installing your brand of air conditioner.

For additional tips on AC repair and maintenance, reach out to a local HVAC technician.