AC Smells Musty? Here is What to Look Out For

ac smells musty

An air conditioner is a great way to provide much-needed cool air to your room. However, a properly functioning air conditioner must not produce smelly air. If you feel that the air conditioner smells musty when turned on, there are reasons why you must not ignore it. A musty-smelling air conditioner usually indicates a deeper problem, which might be severe.

An unusual smell coming from the air conditioner can be indicative of a few problems, the most common of which is mold infestation. Other less severe problems that might occur are dust buildup, dirty drain pans, etc. No matter the cause, it is important to check your air conditioner to avoid paying a bigger check later on.

What are the causes of a musty-smelling air conditioner?

There are numerous problems that can lead to a musty smell from your air conditioner. An air conditioner at its peak maintenance must produce air free of any odor. Regular cleaning and maintenance of your air conditioner are extremely important to maintain its good health.

Mildew buildup on dirty filters

The air conditioner filter is the part that catches the dirt from outside to purify the air that is pushed outside into the room. Therefore, without regular cleaning of the filter, it might be full of dirt that needs to be cleaned. Washing the filters is important to remove all the dirt. A dirty filter catches moisture from the air, producing favorable conditions for mold and mildew. This growth causes a musty smell when the air conditioner is switched on. 

The musty smell can be avoided by regularly cleaning the air conditioner filters. However, in severe cases, they might even have to be replaced. Another common problem associated with a dirty filter is the deposition of dirty water on the evaporator coils. 

This causes the issue of frozen evaporator coils, as the airflow is obstructed, and the humid, warm air freezes on the coils. Frozen coils interfere with the working of the air conditioner and produce a bad smell due to the buildup of dirty frozen water.

Blocked and dirty drain pan

The job of a drain pan in an air conditioner is to catch the condensed water that is stripped away from the air during the cooling process. Thus, the water needs to flow out from this drain pan in a  steady motion. However, if the air conditioner is old, the drain pan or durian line becomes clogged with stagnant water. Mold is attracted to standing water and collects in this moist environment, producing a musty smell.

The best way to avoid mold buildup in the drain pan is to clean it yourself or get your air conditioner serviced by an expert. An HVAC expert can analyze the entire system and clean the according parts, thereby making sure that your air conditioner is now free of any mould buildup.

Dust on the heating elements

Dust buildup on the heating components of an air conditioner can also make your air conditioner smell musty. However, this smell is more of a dusty and burning smell, indicating the burning of dust when the heating coil of your air conditioner gets heated. 

If you happen to continue experiencing such a smell, there might be an even more severe problem with the electrical wiring or furnace. To know what is the actual problem, you need to seek professional assistance. An HVAC expert will analyze the cause and take the necessary action.

Mould buildup in the ductwork

Condensation buildup in the ductwork can lead to serious mould buildup. The ductwork that is not cleaned regularly grows mould easily due to the dark, dirty, and damp environment that it creates. The mould spreads its spores that are usually blown into your room when the conditioner pushes out air. This not only produces a musty smell but can also lead to severe problems like allergies, irritation, etc. 

You must avoid breathing in mould spores. To keep your ductwork mould-free, it is essential to get it properly cleaned. The best way to ensure that is to get it cleaned professionally at regular intervals.

Dirty and blocked condensate line

The condensate line is a part of the condenser unit of an air conditioner. The condenser unit is outside the home, and the condensate line is used to channel the water from the air conditioner to the ground or drain, depending on the place of installation. As this pipe remains outside, it is way more prone to dirt, dust, mud, and bacteria. 

This buildup can make your air conditioner smell musty and interfere with the health of your air conditioner. To avoid the buildup in the condensate line, it is essential to clean it every month or two, depending on how dirty it gets. Regular cleaning of the pipe ensures that water can leave the air conditioner properly without remaining in the pipe itself. 

What are the solutions to a musty-smelling air conditioner?

Although we went through numerous problems that might lead to your air conditioner producing musty-smelling air, it is important to know that the most important reason behind such a problem is mould buildup in one or many parts of the air conditioner. 

Mold can grow in the filter, ductwork, drain pipe, etc., and causes an unpleasant musty smell when the air conditioner is switched on. Severe mold buildup can spread to other parts of your home, like the walls or floors, thereby damaging them. It is thus important to treat mold buildup as soon as possible.
Regular cleaning and maintenance of your air conditioner or HVAC system are thus crucial in order to avoid any form of mold buildup. The best way forward is to set up a professional consultation with experts like those at Hurliman Heating – we’ll make sure your home’s air quality is vastly improved and well-maintained throughout the year.

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