My Lights Flicker When I Use My HVAC. Should I be Concerned?

April 22, 2019

Most things in your home rely on electricity—from charging your cellphone 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 expect. For many homeowners, this stress can come to a head when lights flicker after their HVAC system starts to run.

The question remains: Do dimming or flickering lights at the beginning of HVAC cycles indicate a serious electrical problem? It differs depending on the situation.

When are dimming or flickering lights considered common?

If you’re noticing 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 major 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, have a lower amount of power available to them.

If this is the single 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 Lanz Furnace and Fireplace. We’ll review your system and see if an equipment upgrade or circuit changes can solve the problem.

When should I worry about flickering lights?

Flickering lights can also indicate a more serious matter. Don’t investigate yourself. The problem could be hazardous for you or your home. Call a professional if you see:

  • Lights that continue to flicker. The normal flickering that occurs 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 continually at any other time—you could have a problem with your wiring.
  • Lights that dim considerably. When you experience usual dimming, the effect is enough that you notice a small, brief change. If the intensity of your lights abruptly drops considerably, you may have something wrong with the outdoor compressor on your air conditioner.
  • A circuit breaker trip when you switch on 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 space (powered by a specific circuit), they are attempting to protect you from a problem with your circuit. While it could 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 technician in to take a look. The team at Lanz Furnace and Fireplace is here to provide support. When you need us, you can give us a call at 608-291-3606 or make an appointment online. We’ll make sure everything is in order so your household can feel safe in your home.