If your lights dim or flicker when your air conditioner turns on, you run the microwave, or use a hair dryer, never ignore it. Lights dimming is often a sign of a larger electrical system issue, like a panel that doesn’t have enough capacity or is breaking down.
The situation calls for electrical repair, but the details vary depending on the cause. The solution could range from replacing a failing circuit breaker or worn connections to upgrading the whole electrical panel.
For common causes, solutions, and when to call an electrician for help, read this expert guide from the Brightest Bunch Electrical team.
Is It Normal for Lights to Dim When Appliances Turn On?
If you’ve lived in an older house, a slight dimming of the lights may seem normal. However, whether a house is old or new, dimming lights isn’t something to take lightly. It’s easy to ignore if it doesn’t interfere with your daily life, but it can indicate problems like a worn-out panel, stressed wiring, or overloaded circuits. If there isn’t enough electrical capacity, it puts stress on both the electrical system and your appliances.
For example, a lot of older houses didn’t originally have a modern HVAC system. If someone added one, they might not have upgraded the electrical panel to match the added electrical demand. The AC probably works, but it can draw down too much power and dim lights on other circuits. This is a sign that your house needs a panel inspection. The same goes for newer homes where the homeowner added systems like an EV charger or a plug-in power saw.
This problem is becoming more common as people add more electrical devices to their homes. For example, magnetic induction and electric stovetops are more common today. These often require a 50-amp-or-higher circuit. Older houses sometimes have panels that barely support 100 amps across the property. That’s why turning on the stove while the AC is on might cause the lights to dim.
Electrical Red Flags
Any lights dimming in your home are cause for an electrical inspection, just in case. However, there are some additional red flags to look out for. If the dimming lasts more than two seconds, then the electrical system is struggling. Likewise, turning on small appliances causing dimming could mean that you have a more urgent need for added capacity. Lights dimming in multiple rooms is also a stronger warning of an overloaded electrical panel. Increasing frequency of dimming indicates that a breaker or the panel might be failing.
What Causes Lights to Dim?
Insufficient electrical capacity leads to overload, with capacity limited either at the panel or on the specific circuit. Many older houses have panels with a total capacity of only 100 amps. The modern standard for residential use is a 200-amp panel.
Dimming also occurs as circuit breakers and panels age. A circuit breaker’s internal contacts wear out, especially if they’ve tripped a lot. As they do, they become less reliable. Lights dimming in one or two rooms may indicate that your circuit breaker is at the end of its lifespan.
Loose outlet connections are another worrying possibility. A wire or a connector where the appliance plugs in could be loose. This limits the power to the appliance, forcing it to draw more energy. If the lights dim when you plug something in, electrical repair can prevent further damage and safety issues.
Degraded or insufficient wiring can also draw power, causing dim lights. For example, someone may have installed a 20-amp device, like a refrigerator, on a 15-amp circuit. This should trip the breaker, but it doesn’t always happen. Appliances like microwaves and coffee makers often have high initial draws. In some instances, home rewiring may be necessary.
What You Can Check Before Calling an Electrician
These things are worth trying before calling an electrician.
- Move the appliance to a different outlet.
- Avoid running multiple high-draw appliances at the same time.
- Check that the appliance’s plug and outlet aren’t loose.
- Look for heat damage at the outlet.
- Reset any tripped breakers.
When an Electrical Panel Upgrade May Be the Right Solution
If your house was built before 1990, there’s a good chance the panel supports 100 amps or less. We can inspect the panel and verify whether an upgrade to 200-amp power is necessary. A panel may also suffer from corrosion or other wear. If you have to replace the panel, then this is a good time to upgrade. Our electricians handle all kinds of panel installation and repair projects.
Brightest Bunch Electrical serves Buford, GA, and beyond. We have been in business since 1998, and our company is licensed and insured. Financing is available on approved credit for installations.
Contact Brightest Bunch Electrical today if you see lights dimming when appliances come on in your Buford home.
