What Does It Mean When The Air Conditioner Starts Smoking?

Posted on: 14 September 2020

When you turn on your air conditioner, you don't expect it to start bellowing smoke. Unfortunately, when it does, it can indicate something has gone wrong with your machine that needs to be fixed as soon as possible. Here are three reasons your A/C unit is smoking and what can be done about them.

It May Not Actually Be Smoke

Believe it or not, there are actually a couple of benign reasons your air conditioner could be smoking, with the most common being dirt. If your unit has been sitting for a while, a layer of dust has probably settled on it, and the smoke is likely from some of the components burning it off as they heat up. You can tell this is the case because there will be a mild smell accompanying the smoke and both will stop after a few minutes.

Another harmless reason your air conditioner is smoking is actually due to the comingling of cold and warm air. When air of differing temperatures interacts, it can condense into water droplets which turn into fog.

So, the smoke may not be smoke at all but, instead, fog formed from cold air produced by the A/C unit meeting the warm air surrounding it. This is likely the case if the smoke is white and there is no scent.

Usually, it goes away once the air around the air conditioner reaches the same temperature as the air coming out of it. If it doesn't, check your filter. A dirty filter inhibits airflow, which may cause the water vapor to hang around longer than normal.

The Unit May Be Overheating

If smoke continues to blow out for more than a few minutes and it's accompanied by an electrical smell, then you have a serious problem on your hands. The smoke and scent likely indicate your unit is overheating and damaging the electrical components in the machine. If the unit keeps tripping the circuit breaker or continuously cuts off shortly after turning on, then this is probably the problem.

The most common cause of overheating is a dirty air filter. As noted previously, a clogged filter stops air from flowing freely throughout the machine, which can cause it to get dangerously hot.

Although you'll want to check the filter and replace it if necessary, it's best to turn the A/C off and call a repair company for service. The burning smell typically means the affected parts have been damaged and need to be replaced. Continuing to use the machine after this will simply cause further damage and may even present a fire hazard.

The Fan Belt or Motor May Be Failing

Air conditioners have a lifespan of 15 to 20 years. Like any mechanical device, parts wear out over time. So, if your air conditioner is old, chances are good that the smoke coming from it signals that one or more parts have broken down.

It can be any part causing the problem, but the most likely culprit is either the fan belt, the fan motor, or both because these operate longer and harder than any other part in your unit. If the fan doesn't move or only runs sometimes when you turn on the A/C unit or there's a buzzing or rattling sound coming from inside the machine, then it's a good bet that your fan motor is failing.

There's not much you can do here except replace the burned-out parts. Ideally, you should have a professional HVAC tech inspect the unit before you spend money fixing this particular item because they can make a more accurate diagnosis, which will save you time and money if the fan motor isn't the source of the smoke.

For help with your broken air conditioner, contact a local 24/7 A/C repair company.