The Lights Flash When the HVAC Starts. Should I Be Concerned?

Lots of things in your home depend on electricity—from charging your phone to keeping the temperature inside where you want it. That’s why it’s frustrating when electricity in our homes doesn’t work the way we want it to. For many homeowners, this stress can come to a head when lights flicker after their air conditioning or heating system starts to kick in.

The question remains: Do dimming or flickering lights at the beginning of HVAC cycles show a serious electrical problem? It depends.

When are dimming or flickering lights considered common?

If you’re experiencing dimming that lasts for a fraction of a second when your HVAC begins, it probably isn’t something to be concerned about.

While it might not feel like it, your home has a certain amount of electricity it can use at any given time. Large appliances—like your HVAC system—need a significant amount of electricity to start up. When those appliances turn on, they take a larger amount of the available electricity. This means the other appliances in your home, like your lights, have less power available to them.

If this is the lone issue you are facing, your lights should dim for less than a second and quickly return to full brightness. If you’re irritated by the flickering, schedule an appointment with Bigfoot Mechanical. We’ll review your system and see if an equipment upgrade or circuit changes can alleviate the problem.

When should I be concerned about flickering lights?

Flickering lights can also signify a more serious matter. Don’t try to figure this out by yourself. The problem could be unsafe for you or your home. Reach out to a professional if you see:

• Lights that continue to flicker. The normal flickering that takes place when there isn’t enough power to support all appliances in your home should last a fraction of a second. If your lights continue to flicker on and off when you start your HVAC system—or consistently at any other time—you could have a problem with your wiring.
• Lights that dim significantly. When you experience typical dimming, the effect is enough that you notice a small, brief change. If the intensity of your lights unexpectedly drops considerably, you may have something wrong with the outdoor compressor on your air conditioner.
• A circuit breaker trip when you turn on your HVAC. Circuit breakers are a key part of your home’s electrical system. When they trip and shut off power to a part of your home (powered by a specific circuit), they are attempting to protect you from a concern with your circuit. While it may be that you have too many appliances on the same circuit, it’s wise to bring a professional in to check that there isn’t a more serious problem.

Any time your HVAC system and lights don’t work together, it’s a good idea to call a professional in to take a look. The team at Bigfoot Mechanical is here to help. When you need us, you can give us a call at 509-392-8770 or make an appointment online. We’ll make sure everything is in order so you can feel safe in your home.