Low voltage at an outlet isn’t only an extremely annoying problem, but also a potential cause of serious damage to your household appliances, and even some bigger issues in your home, such as a fire hazard.
Therefore, if you notice this issue anywhere in your home, it is of utmost importance to react promptly and solve the problem. As with any other household issue, it is necessary to understand what’s happening before taking any action.
In this guide, we will not only talk about the solutions to this problem but also the possible causes, so you can easily recognize them and prevent this from happening in the future.
What causes low voltage at an outlet?
Getting to the bottom of the issue isn’t only necessary so that you can address the problem adequately. This kind of approach also allows you to prevent the issue from expanding, reoccurring, or triggering other potential issues in your household.
Low voltage at an outlet is normally caused by a voltage drop, which is basically a drop in your home’s electrical circuit. While a small drop could be neglected, if it is drastic, it could trigger serious problems.
What is considered drastic? Taking a 120-volt distribution panel as a reference, the biggest drop you should tolerate is by 3.5 volts (or fewer). Anything more serious than that requires immediate action, as you want to protect your appliances and your household.
Sometimes, the core issue will be obvious. Other times, you will need to do some troubleshooting to discover what’s wrong.
Depending on how much experience you have in these matters, you may be able to perform the troubleshooting yourself or contact a professional if needed. For a DIY troubleshooting test, you will need a voltage meter (the most accurate method) or a lamp.
In case you have a voltage meter, it will be easy to test the power output and determine its level. On the other hand, if you’re using a lamp, it will not be as accurate, but you can definitely detect a dead/faulty outlet.
The next step would be to inspect the main circuit breaker in your home for any faulty breakers or fuses. In case you notice that any of the elements are damaged, it is necessary to repair or replace them – depending on the severity of the issue.
Also, it is important to check if the outlet which is not getting enough power is the GFCI outlet (ground fault circuit interrupter). If this is the case, you should also check the status of the GFCI circuit breaker, and reset or repair it, depending on its state.
Besides the factors we’ve discussed, what is it that could cause this kind of havoc in your home? Let’s talk about some of the most common reasons behind a low voltage.
1. Normal wear and tear
Just like any other appliance and part of your household, electrical outlets are prone to normal wear and tear over time – especially those you’ve used frequently. What actually happens is that plugging and unplugging device cords damages the outlet connections.
If the connections inside the outlet are damaged, it will not be able to put out full power, and you’ll experience low voltage. Also, these kinds of damages in the internal wiring of the outlet could lead to bigger defects and issues.
2. Damaged/Loose wiring in the electrical panel
While inspecting the wires in the electrical panel, keep an eye out for any signs of corrosion or fire. In case the electrical wiring is damaged, you will have to either replace the wires or the electrical panel altogether, to avoid any bigger issues. Of course, this is a task for an electrician.
Also, you’ll need to inspect the wire connectors and make sure they’re secured and tightened. In case they’re loose, this could be the reason behind the outlet not putting out full power. As we’ve mentioned, it is necessary to locate any loose screws, too.
If there is a low voltage in a circuit, this will not only affect the outlets, but also the lights and the appliances in your home, and it is a much bigger issue than just a faulty outlet.
3. Loose screws in the electrical panel
Inspecting the electrical panel for any issues includes not only checking the condition of the wiring but the screws, as well. Oftentimes, the screws on the electrical panel or the wire connectors haven’t been tightened enough.
It is necessary to make sure that all the screws are tightened, as this will ensure that the wiring is stable and well-connected. Remember to turn the power off in your electrical panel before inspecting all of its elements – wiring and screws included.
Once you’re done inspecting and fixing/replacing the elements in the panel, turn the power back on.
4. Imbalance in wiring
Sometimes, the problem behind a voltage drop in the house is an imbalance in your electrical system. As you may or may not know, the transformer has three different wires coming into the house, and sometimes, they may vary in quality.
Each of these three wires is supposed to carry a certain amount of load, and since the load is split between them, none should be overburdened. However, sometimes one wire could be unbalanced, or weaker than the others, causing problems or even resulting in failure.
If one wire distributes more electricity than the others, it will certainly become overwhelmed at a certain point, and the voltage will be affected. Low voltage reading at the light switch could also result from this issue.
5. Overload and distance from the main power plant
While the previous factors are definitely something we can improve and fix, there are also those that we can pretty much do nothing about. Sometimes, when you notice the outlet not getting enough power, the problem is far beyond your home.
If you notice that the voltage is particularly low in certain periods of the day, it could be that the entire system is overloaded – and not just your own electrical system. Low voltage can occur as a consequence of the overload of the system in your area or town.
On the other hand, the distance of your home from the main power plant plays a significant role in the voltage you get, as well. Households located closer to the main power plant will get a better voltage, as opposed to those positioned far away.
Unfortunately, since the electricity has to travel farther to reach the homes in the rural areas, low voltage is a common issue – especially if there aren’t many houses. The more houses – the denser the electrical signal.
How to fix low voltage at an outlet
As you can already imagine, certain factors simply cannot be changed or improved. For instance, the distance of your home from the main power plant, as well as the occurrence of a daily overload, are beyond your power.
On the other hand, any problem in your own household can be accessed, whether you’d like to work on it yourself or hire a licensed electrician. When it comes to dealing with bigger issues, especially if you’re inexperienced, we definitely recommend hiring an expert.
1. Repair or replace damaged wiring
Whether it be the wiring in the outlet itself, or the electrical panel, it is prone to wear and tear, as well as corrosion and other types of damage. Also, it could be that the wires haven’t been secured, and a loose wire will certainly cause low voltage.
In this case, it is necessary to fully inspect and detect the faulty wires. In case of loose wiring, all you need to do is secure them and put them back into place, making sure to tighten all the screws – as this can be an issue, too.
In case of corroded or damaged wiring, it is necessary to repair or replace the wires. In the majority of cases, replacing old and rusty wiring is the best decision you can make, and the safest choice. Repairing them is usually just a short-term solution.
2. Replace the outlet
Just like the wiring is prone to wear and tear – so are the other elements of the outlet. It could be that the internal elements have been damaged due to frequent use, or that a faulty appliance or cord has caused the problem in the structure of the outlet.
Either way, the easiest way to go about this is to replace the outlet, especially if it hasn’t been changed for years. Of course, this step will only be successful if you’ve ruled out all the other factors affecting the voltage in your household.
Replacing an electrical outlet is something you can do on your own, especially if you follow each of the following steps:
- Turn off the power in your home from the main circuit panel.
- Remove the cover plate by unscrewing all the screws holding the plate.
- Use voltage testers to check if you’ve turned off the power.
- Remove the receptacle from the electrical box by unscrewing it and pulling it out while the wires are still attached.
- Detect the wires and remove them.
- Inspect the old receptacle to see if the break-off tab (which connects the terminals on both sides of the receptacle) is still there. If you notice that there’s no break-off tab, you should carefully remove it from the new receptacle with pliers.
- Add the wires to both terminals of the new receptacle by attaching them. If there is also a green ground wire, it should be connected to the corresponding green terminal on the very receptacle, or to the electrical box.
- Place the new receptacle into the box and secure it using screws.
- Finally, add the cover plate over the electrical box and secure it with screws.
- Now you can turn the power on and test your new outlet.
Can you fix low voltage at an outlet?
Yes, this issue can be fixed as long as the problem concerns your household only. If the problem concerns the entire area, there isn’t much you can do about it.
Old outlets, loose or damaged wiring, corroded outlet elements, or even bigger issues concerning the electrical panel, as well as the entire electrical system in your household, can definitely be fixed.
However, when it comes to these problems, it is important to be realistic with your abilities and contact an expert if the task is exceeding them.
David Kessler is a CSLB licensed contractor with over 25 years of experience. He is specialized in home building, construction, and electrical works; he also has a keen eye for interior design and, over the years, has collaborated with various architects.
