5 Strange AC Warning Sounds and Odors

When your air conditioner emits an offensive smell or a strange noise, it’s an AC warning sign. For the most part, we treat our air conditioners as “out of sight, out of mind,” and rarely give them much thought until there is an indication that something is wrong. An unrecognized noise or smell from your AC is usually a sign that something has malfunctioned and the unit needs professional repair. Learn some common AC warning signs and what Daniel Island, South Carolina, homeowners can do about them.

A Buzzing Noise

If you hear a buzzing noise coming from your air conditioner, it’s typically a sign of electrical arcing. You should switch off the air conditioner immediately and make an appointment with a professional to inspect and repair the unit as soon as you hear this noise.

Commonly, buzzing is caused by a loose electrical connection or malfunctioning circuit breaker, a faulty condenser fan unit (the large fan outside the building), or a malfunctioning contactor relay switch. A mechanical failure can occasionally cause buzzing if the refrigerant is leaking or bearings are worn. It is imperative that homeowners don’t try to fix electrical problems themselves. Instead, you should always consult a professional.

A Rattling Sound

Rattling is usually the most common sound that owners report about their HVAC systems. While rattling is not as serious as buzzing, it’s best to get the cause attended to before it grows into a more serious problem. Sometimes rattling will come and go or be worse during startup — but it should never be ignored.

An unsecured panel can cause a rattling noise; this occurs when screws work themselves loose. Another cause is when debris enters the air conditioning system and is clogging the air filter. If this is the case, the entire air conditioner system will need to be inspected to prevent it from happening again.

Rotten Egg Smell

The smell of rotten eggs circulating around your house is no joke, but it’s usually easily fixed by a professional. Usually, this AC warning smell occurs when an animal finds its way into the vents and dies. Birds, mice, and rats are the most common culprits.

A more serious problem is a gas leak. Propane and natural gas are both treated with a chemical to make them smell like rotten eggs if the gas is leaking. This is a potentially lethal situation so extinguish any flames, shut off electrical sources, evacuate the house, and call for professional help immediately.

Burning Plastic Smell

The smell of burning plastic is impossible to ignore. Even worse, it can be an indicator that something terrible is about to happen. As with a buzzing noise, a burning plastic smell can be an AC warning that indicates an electrical fault. In this case, something is melting and you need to shut off your air conditioner to avoid a potential fire.

Another common cause is a broken fan belt. When this occurs, the system starts to overheat, causing a distinctive smell. If the fan belt is worn, it may not be driving the fans as needed. This adds stress to the bearings, which can be another source of overheating.

Wet Socks

The smell of wet socks will sometimes be present when an air conditioner is switched on and become less noticeable as air circulates through the system. What causes this is a buildup of biological growth, which breeds thanks to a healthy supply of moisture and dust. This will cause a lot of problems for people who are sensitive to dust and pollen or suffer from respiratory diseases.

This is quite an easy problem to prevent by having scheduled maintenance. Even if your air conditioner is not displaying any of these problems, it should still be inspected and serviced once a year.

If your air conditioner is showing any of these signs, don’t despair! Call M & B Heating and Air at 843-628-1775 to arrange an inspection or repair with one of our experienced technicians.

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