Most common electrical defects in a home inspection

A home’s electrical system is one of the most important systems of the entire residence. The electrical system provides homeowners with power to pretty much everything they need to function on a day to day basis. Without electricity, we wouldn’t be able to do many of the things that we take for granted each and every day.... like charge our mobile devices and tablets! It is important when purchasing a home, to ensure that the electrical system is safe and functional for you and your family. Electrical defects are one of the most common systems that have issues called out during a home inspection. It is also one of the most common systems that prospective homeowner’s get the most worried about when their inspector points out electrical deficiencies. This is because the electrical system, when not wired properly or has damage, can be hazardous to you and your home. This statement is not meant to scare you, but rather to educate you on the importance of making sure your electrical system is functioning as intended, as well as in a safe manner.

Electricity has come a long way since it was first installed in residential homes. As many of you may know, knob and tube wiring is one of the oldest methods of wiring a home, and honestly, it was not a bad method of wiring. However, through trial and error, the electrical system has been constantly upgraded over time, to become more and more safe for the occupants of the home. Today, modern panels offer protection to homeowners via ground-fault circuit interruption (GFCI) and arc-fault circuit interruption (AFCI) breakers, grounding and bonding, and modern circuit breakers instead of fuses.

Many people often ask during the home inspection, “is this house’s electrical system up to code?” Well, that is an easy question to answer, but a more complex one to explain. The majority of the time, the answer is “No”, but that is not necessarily a bad thing. Most of the homes we inspect are resale homes, meaning they are not brand new and people have lived in them for a number of years. So when a buyer asks us if their electrical system is up to code, the answer is “No”, because it is not up to today’s National Electric Code (NEC), because the NEC changes every 2 years. It does not completely change, but things are added and taken out through data driven analytics. What we typically tell the buyers is “No, the home is not up to today’s code, however, when the home was built, it complied with the electric codes at that time, which is considered an acceptable installation.”

Just because the home met the NEC at the time it was built, does not mean we inspect the electrical system and tell the buyer that everything looks good. There may be knob and tube wiring, aluminum wiring, old style Edison fuses, old style screw in fuses, Federal Pacific panels with stab-lok breakers, Zinsco panels with problematic breakers, etc. All of the aforementioned electrical systems were acceptable installations at one time, but due to documented issues, and more safer alternatives, we as home inspectors feel the need to tell our clients about this.

So what are some of the most common electrical defects found in home inspections?

1. Electrical Panel is not bonded- in an electric panel, bonding provides a path of least resistance to the grounding system in the event of a fault. Every electric panel comes with a green bonding screw or bonding strap, and in the main panel (first means of disconnect), the bonding screw/strap should be installed on the neutral bus bar, as the neutrals and ground are connected in the main panel. In a sub panel, the bonding screw/strap should be installed on the ground bus bar, as the neutrals and grounds should remain separated. Why is this so common? Because most of the time, electrician’s either lose for forget to install the bonding screw after installing the panel. We even see new construction panels that aren’t bonded. This is a relatively minor defect, and a very easy one to correct.

2. Double tapped neutrals- On the neutral bus bar, for years the NEC allowed two neutral wires (white wires) to share a single lug on the bus bar. However, it has never been allowed to bundle more than two under a single lug. We see more than 2 wires under a lug ALL THE TIME. It is mostly done out of laziness by the electrician, which is unfortunate. The neutral bus bar typically has plenty of room for all the neutrals to be isolated under their own individual lug, and we still see them bundled together. The reason we call for them to be isolated, is because the more wires under one lug, the higher the chances the wires become loose, which can result in arcing. This is also a relatively minor defect, and a very easy one to correct.

​3. Double tapped circuit breakers- while double tapped neutral wires is relatively minor, a double tapped breaker is a more significant defect. Double tapping has never been allowed by the NEC, although some brands of circuit breakers are rated for two wires under a lug (square D is one of the most common). Double tapping is where two hot wires (black or red wires) are terminated under a single circuit breaker. Loose connections, arcing, and fire can result from this. We typically see this done because a handyman electrician or a homeowner with some electrical experience made some modifications to the panel. This defect can range from simple and inexpensive to repair, to more complex and expensive, depending on if there is room in the panel to add an additional circuit breaker.

​4. Outlet tested open ground- we use a polarity tester to test each individual outlet in the home for proper wiring, and the most common defect we see on our tester is an “open ground”. Usually, the reason for this reading is because the ground wire on that particular outlet is either loose or not connected. This is a very easy fix, as the outlet just needs to opened up, and the ground wire needs to be connected.

5. GFCI receptacles not in wet areas- The NEC has requirements on where GFCI protection should be installed, and it should always be present in areas that are near a water source. GFCI protection has been required at all outside receptacles for quite some time, and we still commonly see receptacles that do not have GFCI protection where required, most commonly outside— even in new construction homes. It is not very expensive to upgrade to GFCI protection, since individual GFCI outlets are sold at hardware stores.