Lights dim when appliance turns on

If your indoor lights frequently dim without warning, your Chicagoland home may have an electrical issue that extends beyond illumination. Since it’s important to understand the problem before taking action, read on for four possible reasons that the lights in your home keep dimming.

Incorrect Light Bulbs

If you notice unusual behavior from lights connected to dimmer switches, you may be using the wrong light bulbs. Most dimmer switches don’t work properly with compact fluorescent bulbs and may cause lights to blink or malfunction. To resolve this issue, just replace any CFLs with the light bulbs that work best with your dimmer switch.

Overloaded Circuits

If running energy-intensive appliances like air conditioners, microwaves, clothes dryers, or hair dryers causes your lights to dim or flicker, it could be a sign that the circuit is overloaded. You can determine whether this is the root of your problem by checking to see if all appliances in question run on the same circuit. Though overloaded circuits aren’t uncommon in older homes, be sure to consult an electrician if your lights continue to dim after you turn off competing appliances or if you suspect a larger issue.

Outdated Wiring

Electricity demands have changed rapidly over the past few decades, largely due to evolving personal and domestic technology. As homeowners require more and more power from their electrical service, many older homes with dated wiring simply can’t keep up, resulting in noticeable voltage drops and dim lights. An electrician can advise you about rewiring and other cost-effective ways to address your home’s outdated wiring.

Power Grid Issues

Lights that dim for an extended period of time might be the result of a brownout or an issue with your electric company. Contact your local utility to find out whether stormy weather has caused a transformer to blow or if significant weather-related demands have compromised electric service in your area.

Isn’t it time you did something about your constantly dimming lights? Contact Black Diamond to discuss your home electricity needs today: (866) 350-4793.

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No, it's not normal for your lights to flicker when you turn on appliances. While you may assume this is just a quirk of your home, it's actually a sign that something dangerous is happening with your home's electrical system. Don't ignore flickering lights.

While the cause of your flickering lights may not be all that complex, any issue that involves wiring or electrical outlets has the potential to be a fire hazard. That's why if your lights are flickering when you turn on appliances, you should contact a licensed local electrician right away. However, we can help you narrow down some of the possibilities behind why appliances make your lights flicker.

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1. A Bulb Could Be Loose

Do a bulb check first if just one light is flickering. The bulb may be a little loose in its socket. While a loose bulb often still turns on, it's usually less consistent than its neighbors.

Luckily, you can fix a loose bulb without any electrical skills. Simply give your lightbulb a turn to make sure it’s twisted as far as possible clockwise and that it feels secure. Just be sure you turn off the light and let your bulb cool for a few minutes before touching it.

2. You Could Be Using the Wrong Light Bulb

You can also troubleshoot for this cause fairly easily. If a dimmer and your flickering lights are connected, confirm you're using the right bulbs. You can do this simply by looking up the rating for the bulbs you're using to see if they're rated "dimmer compatible." 

If they’re not, try swapping them out to see if the flickering stops.

3. A Loose Connection Can Cause Lights To Flicker

Loose connections in a switch or outlet can sometimes cause flickering lights. The error could even be in your meter box or electric panel. 

However, you don't want to go wiggling wires around looking for the loose connection if you don't have experience with this type of thing. Bring in a pro to help you identify a loose connection if you suspect this could be the cause.

While you're evaluating your lighting situation, consider a smoother option like new recessed or pendant LED lights.

4. It Could Also Be an Electrical Overload

All your electronics, appliances, and lights around your home could be drawing too much current, causing the flickering.

Have you recently installed any new appliances? Your home may not be equipped to handle the power load based on its original amp level. A gadget that's drawing too big of a current could cause voltage fluctuations.

If your lights have flickered when turning on appliances for as long as you've lived in the home, your appliances may not be properly grouped on the right circuits. Bring in a pro to confirm that your home is wired properly to handle the maximum allowable load.

If you have an older home, your power level could be as low as 60 amps. While that used to work just fine, things like dishwashers, air conditioners, and smart systems require at least 200 amps to run safely. Consider getting an estimate to upgrade to 200 amps from a qualified electrician. The cost to upgrade an existing electrical system to 200 amps is between $750 and $2,000.

5. Arcing Wires Can Be Dangerous

When separate wiring connections are too close together, or their insulating covers have eroded, you get arcing wires. This happens when electricity jumps from one wire to another. If you hear a “buzzing” sound from an outlet or when you turn on a light switch, you probably have arcing wires. 

The danger here is that two separate connections can start a fire when electricity sparks and jumps from one system to another. A pro can diagnose and fix the problem, usually by replacing the offending wires.

If the electrical system in your home is wired properly, flickering should be so rare that it's essentially nonexistent. If your lights are flickering whenever you use an appliance, this is a fire hazard.

Continuing to draw from a faulty or overloaded power source is a dangerous game to play, so bring in a professional ASAP. While you may simply need to fix a connection, it's possibly time to upgrade your household load capacity.

Related Article

One not uncommon issue microwave owners experience is when the house lights dim while the microwave is on. While it’s not always a critical issue, it can be a sign of issues you may want to take care of, and it can happen regardless of the quality of the microwave oven.

• Before looking into possible issues with home circuitry or wiring, check to see if the issue lies in old or dying light bulbs.
• Dimming or flickering house lights may be an indication of a serious electrical issue outside of the home, in this case contacting your utility company or a professional electrician is necessary.
• The most common cause of dimming house lights during microwave use is the microwave drawing too much power from a shared circuit- use a dedicated circuit for any major appliance.

There are several reasons your home’s lights may dim while the microwave is in use that you can troubleshoot at home. If after you test the microwave and it’s still having problems, there are a few options about what to do next.

Why a Microwave Light is Dimming During Use

Experiencing dimming of your kitchen lights or other home lights while your microwave is being used can be alarming and a sign of various issues both in your home electrical system and your microwave. Here are the most common reasons house lights dim while your microwave is in use and how you can troubleshoot for it. If your lights are dim and your microwave is not heating, you probably have a separate issue. Click the following for a guide on another common microwave issue- how often to replace a charcoal filter.

Dimming or flickering lights are almost always due to a microwave drawing too much power from a circuit, though the underlying issues can vary.

Overloaded Circuits

The electrical circuits for any home or apartment have a limited amount of voltage they can draw before being overloaded. An overloaded circuit is the most common reason that lights in a house dim, and it can be tested fairly simply by checking to see if the microwave is on the same circuit as the lights that are going dim.

Any large appliance like a microwave, air conditioner, vacuum cleaner, or dishwasher should always be put on a dedicated circuit to avoid this issue. Even small appliances like a hair dryer can draw too much power for some circuits and cause dim lights and can require a separate circuit.

Faulty Wiring

Another culprit for this issue, especially in older homes and apartments, is faulty or poorly installed wiring. Wiring that’s older or installed improperly won’t necessarily be able to meet the power demands of large appliances and can easily cause brownouts and light dimming during the use of an appliance.

If you suspect this is the issue, it’s worth trying to find out how old the wiring is in your home, or acquiring the services of a repair technician to troubleshoot it. Modern wiring in your home can prevent many power-related issues like this.

Power Grid Problems

If your home’s wiring is up to date and properly installed and you don’t have any devices drawing too much power for your home’s circuits, there may be an issue with the local power grid itself. Very often this is due to a higher demand on the power grid from multiple homes and buildings than the power grid is capable of handling, causing a voltage drop in some residences. As such, there’s not a lot you can do if this is the situation apart from putting a call to the utility company.

Dying/Old Bulbs

It might seem obvious to mention, but sometimes, dimming lights may actually just be due to bulbs that are dying or poorly connected. It’s always worth checking this first, especially if it’s only one light source dimming and you haven’t changed your bulbs for some time. Luckily, you can easily enough switch to a new bulb.

Neutral Wire Issue

This is an issue that actually has nothing to do with your microwave or other appliance but can be confused with the above issues. Lights that go between bright and dim regularly are very often a sign of a corroded, loose, or failed neutral wire at the main breaker of your building or home, and can be a fire hazard if not dealt with.

If the light dimming issue persists even when your microwave isn’t being used, this is likely the culprit, and you should contact a licensed electrician immediately.

If house lights dim even while the microwave isn’t in use, it may be an indication of a more serious issue with the main circuit or power grid itself, and a professional electrician or the utility company should be immediately contacted.

F.A.Q.S

Why are my lights flickering when I use my microwave?

If your home lights are flickering when your microwave is in use, it could be for the same reason lights sometimes dim during large appliance use- faulty electrical wiring, old light bulbs, a power grid issue, or a failed neutral wire at your main circuit breaker are the most common reasons.

Is it bad if my house lights dim when I use appliances?

If your house or apartment lights dim or flicker when you’re using a large appliance like a microwave, it may not necessarily be dangerous (though it could be), but it’s something to pay attention to. Often, it means your appliance is drawing more power than your electrical system can handle.

Are dimming lights a wiring issue or a power company issue?

They can be either- sometimes they’re due to an appliance being on a circuit that can’t handle the amount of power it draws, and can be solved by plugging the appliance into a dedicated circuit, but if the issue persists even when the appliance isn’t in use, it may be a power grid or main circuit issue.

STAT: The lifespan of a light bulb refers to the number of hours it provides before it starts putting out less illumination. (source)

STAT: The percent of residential electricity used by major appliances in U.S. homes has risen from 17% to 31% in the past three decades. (source)

STAT: The heating effect of strong microwave beams was accidentally discovered in 1945 (source)