The REAL Reason Why Lights Flicker When AC Turns On

Dominic Mitton
By Dominic  • Reviewed by Ben  • Updated:   October 26, 2023
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If your lights flicker when you turn the air conditioner on, don’t worry because this is a very common problem.

The flickering light happens because of the heavy load on electricity as it requires a lot of power to turn on an air conditioner.

However, sometimes flickering light can be caused by very serious problems!

Without any further ado, let’s jump straight into it.

When Can Flickering Lights Be A Problem

Let’s mention some of the cases when you might consider calling a professional to inspect the issue further.

Continuous flickering

A usual flickering happens when there isn’t enough power to turn on the air conditioner and they should last a couple of seconds.

On the other hand, if your lights continue to flicker a few minutes after you turn on your HVAC system, it’s most likely an issue with the wiring.

Smart air conditioners can quickly diagnose the flickering and alert you if there’s an issue with the wiring.

Continuous dimming

When you notice that the intensity of the lights drops and rises significantly, it could be an issue with an outdoor compressor.

There’s a difference between usual dimming and excessive dimming, so pay close attention to it.

I believe a lot of HVAC systems experience dimming, so don’t panic if it’s not too much.

Circuit breaker trips

Every home has its circuit breakers and they can sometimes trip and shut off to protect you from surprising outbreaks.

That’s why your AC might be sending false alarms to circuit breakers or it might be that a lot of appliances are on the same circuit.

If this is the case, I’d recommend seeking professional help as the issue could be a lot deeper.

Should my lights flicker when I turn my AC on?

The answer is yes, they should flicker.

It’s normal for lights to flicker or dim for a few seconds when you first turn your air conditioner.

Also, lights dim up to 5% or more in healthy HVAC systems.

Inverter air conditioners don’t have as large a load as typical air conditioning units, so that’s a big advantage when going with an inverter.

Can flickering lights start a fire?

A lot of times people are worried that flickering light can cause a fire.

The answer is no, at least they shouldn’t.

However, all electrical appliances can cause a fire because they’re powered by electricity, so it could be possible for flickering light to cause a fire in some scenarios.

Still, this would require either the bulb to be extremely hot or for some object prone to fire to be very close to the light source.

If currents were passing through the filament, it could speed up heating and catch something on fire.

That’s why it’s recommended to not put paper or wood near the light source.

I have to repeat that this is an extremely rare scenario and that most times flickering light doesn’t cause a fire.

If your AC stopped working for some reason, you should check out smart ways to cool your room without an air conditioner.

Hey there! I am Benas, the founder and content editor at Home Caprice. Thanks for reading the article. I hope you were able to find what you were looking for. I and my team are here to simplify heating and cooling for everyone. Please have a look at the About page for more details about our website and feel free to check out our editorial process.