Why Lights Flicker or Dim When Your Air Conditioner Runs

You’re sitting down, enjoying a good book. You hear the familiar sounds of your air conditioner turning on. For a brief moment, your lights flicker and dim. In seconds, it’s all back to normal.

Should you be concerned?

What dimming lights mean

The good news is dimming or flickering lights isn’t necessarily dangerous. It depends on timing. Here’s why.

Electricity enters into your home at a constant flow. Because your air conditioner requires a lot of power to start, it can temporarily divert the flow from areas to allow your AC to start. As long as the lights flicker for a second or less, and your lights don’t lose more than a small percentage of their brightness, you might be okay.

If you notice it, it’s a good idea to keep an eye out for when it occurs. Does it happen every time your air conditioner turns on? Have you recently upgraded and installed a new AC unit? Does it seem to be worsening over time? If you’re nervous or have questions, it’s better to call and get it checked out.

When flickering lights aren’t okay

When you start to pay attention to when flickering occurs, you may notice patterns that make it more troublesome. Does it happen only in certain parts of your home? Does it occur more frequently when more than one appliance is operating? How old is your home?

Older homes especially have more trouble keeping up with demand. If your home was built more than 30 years ago, the electrical system wasn’t built for today’s modern living. It could be draining your system. It could be wiring going bad. It could be a breaker box that’s failing.

Also, pay attention to how much power you’re actually losing. While a slight dimming can happen, if you’re losing up to 40 percent of a light’s brightness or more, it could be a sign your AC unit is having difficulty starting. Think of an air conditioner’s motor like you would a battery. It needs a burst of energy to start. If it has trouble starting, it’s going to pull energy longer from the source, and be noticeable for longer periods of time. One of our technicians can check out your air conditioner and ensure it’s in good working condition.

Have a question about your air conditioner? Have a question about the way electricity flows through your home? We can help. Give us a call today.