Why Your Lights Flicker When the Heat Kicks On — and What to Do About It

Have you ever noticed your lights dim or flicker the moment your furnace turns on? It’s a common issue, especially in older homes, and while it might seem harmless at first, it could point to an underlying electrical problem that shouldn’t be ignored.

At Albritton Service Company, we provide both HVAC and electrical services to homeowners throughout Ruston and the surrounding areas. When your lights flicker every time the heat kicks on, it’s often more than just an annoyance—it may be a flickering lights electrical issue in Ruston LA that requires professional attention.

Let’s break down why this happens and what steps you can take to resolve it safely and effectively.

Is It Normal for Lights to Flicker When the Heat Turns On?

In short: occasional flickering may be normal—but frequent or intense flickering is not. When your heating system starts up, it temporarily draws a large amount of power. This sudden demand can cause a brief voltage drop, which in turn causes your lights to dim or flicker for a second or two.

A one-time flicker during startup—especially with older furnaces or heat pumps—might not be cause for alarm. However, if:

The flickering happens every time the furnace turns on
Lights flicker or dim in multiple rooms
The flickering is getting worse over time
You hear buzzing or humming sounds when the lights flicker
Other appliances or electronics seem affected

…it could signal a bigger electrical issue that needs to be addressed.

Common Causes of Flickering Lights When the Heater Runs

Here are some of the most common reasons you might experience flickering lights when your heat kicks on:

1. Voltage Drop Due to High Power Demand

Your furnace draws a significant amount of power when it starts. If your home’s electrical system isn’t designed to handle the load efficiently, the result may be a noticeable voltage dip—causing your lights to dim briefly. This is especially common in older homes with outdated electrical panels or wiring.

2. Shared Electrical Circuits

In some homes, your furnace and lighting may share the same circuit. This setup can cause interference when both are drawing power at once. Ideally, your HVAC system should be on a dedicated circuit to avoid this kind of competition for power.

3. Loose or Aging Electrical Connections

Loose wiring connections, corroded terminals, or outdated breakers can cause inconsistent power delivery, which shows up as flickering or dimming lights. This is not only annoying—it can be a fire hazard.

4. Undersized Electrical Service

If your home’s electrical service panel is too small for your overall power usage—especially if you’ve added new appliances or HVAC systems in recent years—you may experience frequent voltage drops and flickering. Upgrading your panel can help ensure your home’s electrical system is up to the task.

5. Faulty Furnace Components

Sometimes, the issue isn’t the electrical system at all. A failing blower motor, capacitor, or startup relay in your furnace could be drawing more power than usual or creating sudden surges that affect your lights. If your heating system is older, it might be time for a professional tune-up or repair.

When to Call a Professional

If you’re unsure whether the flickering is normal or a warning sign, it’s always best to play it safe and contact a licensed electrician or HVAC technician. At Albritton Service Company, we specialize in troubleshooting these overlapping systems. Our team can determine whether the issue is electrical, HVAC-related, or a combination of both.

You should definitely give us a call if:

Lights flicker in multiple areas of your home
The flickering is accompanied by burning smells or buzzing sounds
Circuit breakers trip when the heat turns on
Lights dim significantly or for more than a second or two
You’ve noticed other electrical issues in the home

Don’t wait for the problem to worsen. We’re always happy to inspect your furnace and electrical panel to determine the safest, most cost-effective solution. Learn more about our electrical services and how we can help address the issue quickly.

What You Can Do in the Meantime

While waiting for a technician to inspect your system, here are a few basic things you can check:

Replace Old Light Bulbs: LED and CFL bulbs are more sensitive to power fluctuations. Swapping them out for standard incandescent bulbs (temporarily) might help confirm if the issue is related to voltage drops.
Avoid Running Multiple High-Energy Appliances at Once: Try not to use the microwave, dryer, and furnace all at the same time if flickering is a consistent issue.
Listen for Unusual Furnace Sounds: If your heater makes loud startup noises or takes longer than usual to turn on, it may be contributing to the problem.

Remember, these are just temporary measures. If you want lasting peace of mind, it’s best to get a professional assessment.

How Albritton Service Company Can Help

Our team has years of experience working on both sides of this issue—electrical and HVAC. That means we’re uniquely equipped to determine the true cause of flickering lights when your heater turns on. Whether the solution is as simple as tightening a few connections or as complex as upgrading your electrical panel, we’ll walk you through your options and offer upfront pricing with no surprises.

We’ve helped homeowners across Ruston get their homes back to safe, energy-efficient operation—and we’d be happy to do the same for you. Visit www.albrittonservice.com or give us a call at 318-251-0885 to schedule an inspection.

Stop Ignoring the Flicker—Call Albritton Today

If flickering lights are becoming the norm every time your heat turns on, don’t brush it off. What seems like a minor annoyance could be a sign of a larger issue waiting to happen. From diagnosing the problem to making professional repairs, Albritton Service Company is your trusted source for fixing any flickering lights electrical issue in Ruston LA.

Call us today and get to the bottom of the flicker—before it becomes something more serious.