The Lights Flash When I Use My HVAC. Should I Be Worried?

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

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

When are dimming or flickering lights considered normal?

If you’re seeing dimming that lasts for a fraction of a second when your HVAC kicks in, it usually isn’t something to be stressed about.

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

If this is the only 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 Three Rivers Heating and Cooling. We’ll review your system and see if an equipment upgrade or circuit changes can alleviate the problem.

When should I worry 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 hazardous for you or your home. Contact a professional if you see:

• Lights that continue to flicker. The normal flickering that happens 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 considerably. When you experience normal dimming, the effect is enough that you notice a small, brief change. If the intensity of your lights suddenly drops considerably, you could have something wrong with the outdoor compressor on your air conditioner.
• A circuit breaker trip when you start your HVAC. Circuit breakers are a critical part of your home’s electrical system. When they trip and shut off power to a part of your house (powered by a specific circuit), they are attempting to protect you from an issue with your circuit. While it might be that you have too many appliances on the same circuit, it’s smart 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 technician in to take a look. The team at Three Rivers Heating and Cooling is here to offer you the help you need. When you need us, you can give us a call at (503) 739-5400 or schedule an appointment online. We’ll make sure everything is in order so your household can feel safe in your home.