Frequently Asked Questions

We know you may have many questions when you need an electrician. The experts at Mario Castillo Electric are here to answer all your questions. We thought we'd answer some common questions we receive regularly.

Don't see your question below? Contact us today and we'll be in contact. 

electrical panels

General Questions

What Payment Methods Does Mario Castillo Electric Accept?

We accept a variety of payment options including e-checks/ACH payment, Venmo, Zelle, credit cards and checks.

Are There Any Financing Options?

Yes. We offer a great financing option through Wisetack that will allow you to pay month-to-month. Many of our customers have already been approved and used this service successfully. Click here to learn more.

Can You Tell Me Exactly How Much This Electrical Job will Cost Me?

Yes, we will let you know exactly what it will cost to get the job done before we begin the job and we will stick to our pricing.

What is a Troubleshoot?

Troubleshooting is the process of isolating and identifying a fault in something so that it can be repaired.

Home Rewires

What is Knob and Tube Wiring?

Knob and tube, or open wiring, was installed from the initial electrical installations in the early 1900s into the 1940s. It is named for the porcelain fittings that were used to support and run cables through wood structures. If it is left alone and no changes have been made to the original installation, and the insulation is still in good, flexible condition, it may still be a safe installation. However, there are a number of issues you should be aware of. If you have knob and tube wiring in your home, you should have it inspected by a licensed electrician.

Can I Stay At Home During The Process?

Based on experience, we recommend customers to find another place to stay during the rewire. This is because your home will be under construction until the final city inspection takes place. 

Do I Need a Rewire?

If your home is 50 years old or older, you probably need to rewire your home. You might be noticing flickering or dimming lights that need to be changed regularly, breakers that trip frequently,  and broken or cracked sockets. Also, if your outlets are not grounded, you don't have enough sockets and the fuse electrical panel is old, rewiring your home, is the solution.

Why Do I Need a Rewire?

Faulty wiring is very dangerous and could result in house fires and other household accidents. An electrical rewire will eliminate safety and health risks caused by old wiring, avoid electrical surges and prevent short circuits, arc faults and overloads which will decrease your utility bill. The new rewire will be in compliance with the National Electric Code which will bring your house to what is currently needed and what is projected for the next 30 years.

What Can I Expect During a Home Electrical Rewire?

Rewiring a house is a significant home renovation project that will affect every wall in your home - but, it’s all to ensure your safety! New wiring will need to be run throughout your entire house, from the basement, to the crawl space, to the floor joists, to the attic. Many holes (10’’x10’’) will be made in your walls and ceilings so we can get to the wires. Once the wires are replaced, we will seal everything with new drywall and texture to match existing walls. You will be responsible for repainting. Click here to learn more.

Solar Solutions

Which is the right solar panel for my home?

Choosing the right solar panel for your home can be difficult. We can help you simplify the process.
Read our blog for more information!

Choosing the Right Solar Panel for Homes in Long Beach and the Surrounding Areas

Which battery should I consider when selecting a solar battery?

Sorting through the sea of solar batteries can be a challenge. Read our blog for more insight!

Mario Castillo Electric Powers Up New Solar Battery Services

NEM 1.0, NEM 2.0 and NEM 3.0 - what is the difference between them? What are the advantages of California's new billing NEM 3.0 policy for solar energy?

Mario Castillo Electric understands the impact of NEM on customers, clients and the services we provide! Read our blog for the benefits and impacts. 

Mario Castillo Electric Sheds Light on NEM 3.0 & Our New Solar Energy Services


How Can I Make My Commercial Building More Energy Efficient?

Buildings constructed more than 20 years ago are likely using energy-sucking commercial lighting fixtures that could do with a modern replacement. According to the DOE, older buildings are collectively wasting $50 billion annually through outdated lighting systems. 20 - 50% of your electricity bill is for lighting. Wouldn’t you like to cut that number down? With the right investments now, we can help you start saving money in the future! Click here to learn more.

Panel Upgrades

Should I change my Federal Pacific panel?

Yes! Mario Castillo Electric's experienced team works on complex electrical panel upgrade projects, including major commercial electrical projects. Learn more about our Electrical Panel Upgrades and the risk of Uninsured Electrical Panels.

What do I Need to do Prior to Getting a Quote for a Panel Upgrade?

Homeowners must request a meter spot check from their electrical service provider. This step is crucial because if your electrical service provider confirms a different location for your panel upgrade, this will affect the cost of the quote. Note: the homeowner must complete this step as the electrical service provider will only speak with the account owner.

What Can I Expect During a Sub Panel Upgrade?

An electrical sub panel upgrade is usually completed in a day. The length of time and exact process will be discussed case by case. Sometimes we have to move the panel, upgrade wires, and make other changes to future proof your home. Click here to learn more.

What Is The Cost For Additional Electrical Upgrades?

If you want to upgrade your lights, add dimmers, install USB outlets or even a new ceiling fan, we will gladly do that without any additional charge. You will only have to provide the new outlets or light fixtures.

What is a Panel Upgrade?

An electrical panel distributes the electricity in your home. It’s that gray box usually found in the wall hallway, bedroom or garage. The power line from the meter outside connects to this box, which contains the circuit breaker switches for your rooms, appliances and garage. Over time, the panel and circuit breakers can have a difficult time keeping up with the demand of your electrical needs. Click here to learn more.

What is a Whole Home Surge Protection? Is It Necessary for my Home?

Today’s homes are more advanced and filled with electronics than they have ever been, and we are increasingly dependent on not only the electronics but the ability to easily charge them. Whole Home Surge Protection provides protection to all the electrical equipment in your home from surges and spikes that can be created outside or even inside your home. It acts just like the high-quality power bars we often buy for our entertainment systems or our computer systems, but instead, it protects all the devices in your home. This means it protects the electronic components of refrigerators, freezers, washers, dryer dishwashers, coffee makers, and anything else that wouldn’t traditionally have protection. We recommend whole home surge protectors be installed in all homes to protect all the electronics.

Electrical Inspections

Why Should I Get an Electrical Inspection In My Home?

There are many reasons. When many of these old houses were built, there was no such thing as a building code. Over the years, you may have worked hard to get your home up to code, but you never know what you may have missed. An electric inspection can help you determine if your home's electrical system is up to code and provide code corrections where needed. Click here to learn more.

Electric Vehicle (EV) Chargers

Does Owning an Electric Vehicle Impact Your Electric Bills?

There are many reasons why people are choosing to buy electric cars. One of the main reasons is that they are much better for the environment than traditional gasoline cars. Electric vehicles produce zero emissions, which means that they don't contribute to air pollution. Additionally, electric cars generally get better gas mileage than gasoline cars. This means that you'll save money on gas in the long run. Click here to learn more.

Is Mario Castillo Tesla-Certified?

YES! We are proud to announce that Mario Castillo Electric is now a trusted Tesla Certified Electrician for installing Wall Connector Chargers! Click here to learn more.

Can EV Chargers Be Installed At Condos and Apartments?

Yes - visit our EV Chargers for Condos page to learn more.

What Incentives are Available For EV Chargers?

An Infrastructure Law has recently been passed. This law represents the largest long-term investment in our nation’s infrastructure and economy, with new federal investments in many projects, including electric vehicle (EV) chargers. Click here to learn more.

What Sort of EV Charging Setup Do I Need?

There are three levels of EV chargers. All electrical vehicles come with a Level 1 electric car charger. Mario Castillo Electric recommends using a Level 2 charger. Click here to learn more.


What's the Difference Between 2 Prong and 3 Prong Outlets?

All outlets have a “hot” slot (the right one) and a “neutral” slot (the left one). When you plug in an appliance, electricity flows from the hot slot, through your appliance, and back to the neutral slot. Outlets are made to handle a certain amount of electricity. (Usually 120 volts). So, what happens if there is more electricity than what it can handle? That electricity has to go somewhere. If you have a 3 prong grounded outlet, that third slot is the “ground” slot. The ground slot sends the extra electricity into the ground. If you DON’T have that third slot, the extra power/watts can go to you or your home, resulting in injury or electrical fires. Click here to learn more.

What Outlets Do I Need In My Bathroom and Kitchen?

Areas with moisture including bathrooms and kitchens need GFCI. GFCI stands for Ground Fault Circuit Interrupter. A GFCI will protect you from electrical shocks by sensing the amount of electricity flowing through the circuit. If the flow becomes too great, the GFCI will shut off the circuit. That is why these types of outlets are required in areas with an increased risk of shock due to water or other electrical hazards. Click here to learn more.

Circuit Breakers

What is a Dedicated Circuit?

The National Electrical Code requires that certain appliances have dedicated circuits. These include refrigerators, stoves, and washers and dryers or any other appliance that consumes more than 1200 watts of energy. Generally speaking, a typical single family home has a minimum of 18 circuits to spread electricity evenly throughout the house. A breaker trips when a circuit becomes overloaded. Click here to learn more.

When is a Dedicated Circuit/Outlet Needed?

First, you can check your breaker box. Are the circuits labeled by room or by device? If it’s only by room, you probably need to add dedicated circuits.

Next, pay attention to when your breakers trip. Maybe using the toaster and the coffee machine at the same time is fine, but the minute you use the microwave or plug in the blender, the breaker trips. This suggests that the kitchen appliances are all sharing a circuit, and your refrigerator needs its own dedicated circuit. Click here to learn more.

What Do You Do When Your Breaker Trips?

Breakers trip when a surge of energy overloads a circuit. Maybe it’s high winds, lightning strikes, or simply overloading the grid with modern appliances. To keep your home safe, the breaker’s safeguard is to switch off. Turning things back on is a simple process. Click here to learn more.

What is the Difference Between a Regular Breaker and an Arc Fault Breaker?

All breakers are designed to prevent the wiring from becoming overloaded and will automatically turn off if the circuit is overloaded. Arc fault breakers have the additional ability to sense arcing in a circuit. Arcing happens when loose or corroded wiring connect and cause an electrical current to spark - or arc.  The hot wire touches a ground, but doesn’t trigger a traditional circuit breaker. Arcs are extremely hot and a serious fire hazard. Click here to learn more.

Ceiling Fans

What Type of Ceiling Fan Should I Buy?

There are several things to consider before purchasing a new ceiling fan including diameter, height, and more. Click here to learn more.