Electrical Inspection Checklist: What Every Inspector Needs to Know

Electrical findings are the most common safety hazards in home inspection reports. Not because houses are wired dangerously — most aren't — but because electrical systems accumulate problems over decades of renovations, DIY projects, and deferred maintenance.

A homeowner replaces a light fixture and reverses the hot and neutral. A contractor adds a circuit but double-taps a breaker instead of installing a new one. Someone finishes a basement and covers knob-and-tube wiring with insulation. None of these are malicious. All of them are hazards.

This is the complete electrical inspection checklist — what to look at, what the findings mean, and what separates a code violation from a genuine safety concern.

Service Entrance and Main Panel

The panel is where you start. It tells you the story of the home's electrical history — original installation, upgrades, additions, and mistakes.

Service Capacity

• 100 amp: Standard for older homes (pre-1980). Adequate for basic needs but may not support modern loads (EV charger, electric range, heat pump, central AC all on the same service)
• 150 amp: Common in mid-range homes built 1980s-2000s
• 200 amp: Current standard for new construction. Handles everything a modern home needs
• 400 amp: Large homes or homes with significant electrical loads

Check the main breaker rating. It should match the service entrance cable and meter base rating. Mismatches indicate someone upgraded part of the system but not all of it.

Panel Brand and Type

Some panels have known defects. Flag these immediately:

• Federal Pacific Electric (FPE) Stab-Lok: Breakers have a well-documented failure to trip under overload conditions. The Consumer Product Safety Commission investigated these. Recommend evaluation by a licensed electrician.
• Zinsco / GTE Sylvania: Similar tripping failures. Breakers can melt to the bus bar and fail to trip. Recommend evaluation.
• Challenger (certain models): Some bus bar connection issues reported. Less severe than FPE/Zinsco but worth noting.
• Pushmatic: Older style with push-button breakers. Not inherently dangerous but parts are obsolete, making repairs difficult.

Panel Interior (if cover can be safely removed)

• Double-tapped breakers: Two wires under a single breaker terminal that's rated for one. Common, easy fix, but a defect. Exception: certain Square D and Cutler-Hammer breakers are rated for two conductors — check the label.
• Improper breaker brands: Breakers must match the panel manufacturer (or be UL-classified for that panel). A GE breaker in a Square D panel isn't just wrong — it may not fit the bus bar properly and can arc.
• Signs of overheating: Melted wire insulation, discolored breakers, heat damage on the bus bar. Any of these = immediate safety concern.
• Wiring organization: Not a defect per se, but a rat's nest of wires in a panel suggests unprofessional work throughout.
• Unused openings: Must be covered with blanks. Open knockouts in the panel box violate code and create a pest/debris entry point.

Panel Exterior

• Location: Panels should be accessible. In a closet full of storage? Behind a furnace? These are access issues.
• Working clearance: 30 inches wide, 36 inches deep, 78 inches high minimum in front of the panel. This isn't optional — it's a safety requirement for emergency shutoff.
• Labeling: Circuit directory should be filled out and accurate. Most aren't, which isn't a safety issue but is worth noting.

Branch Circuit Wiring

Wire Types

Identify what's in the house:

• Romex (NM-B): Standard modern residential wiring. Copper conductors with ground. This is what you want to see.
• BX / AC (armored cable): Metal-sheathed cable, common in older homes and apartments. Legitimate wiring method. The metal sheath serves as the ground path (with a bonding strip in newer AC cable).
• Knob-and-tube (K&T): Pre-1950s wiring. Two separate conductors run through ceramic knobs and tubes. No ground conductor. Not inherently dangerous IF it hasn't been modified — but it often has been. The problem: K&T was designed to dissipate heat through air circulation. Burying it in insulation causes overheating.
• Aluminum branch wiring: Used extensively from 1965-1975 due to a copper shortage. Aluminum expands and contracts more than copper, which loosens connections over time. Loose connections = heat = fire risk. The wire itself isn't the problem — the connections are.

Wire Sizing

Common residential circuits:

The key check: wire size must match or exceed the breaker rating. A 14 AWG wire on a 20-amp breaker is a fire hazard — the breaker won't trip before the wire overheats. This is one of the most dangerous DIY mistakes.

Junction Boxes

• All wire connections must be inside a covered junction box. No exceptions.
• Open splices in attics, crawlspaces, and walls are common findings and legitimate defects.
• Junction boxes must remain accessible (not buried in drywall or insulation).

Outlets and Switches

You won't test every outlet in the house — that's impractical. But systematic sampling tells you a lot.

Testing Protocol

Use a three-light circuit tester on a representative sample:

• At least one outlet in every room
• All kitchen countertop outlets
• All bathroom outlets
• Garage outlets
• Exterior outlets
• Any outlet that looks visually different (newer cover plate in an old house = recent work)

Common Findings

Reversed polarity: Hot and neutral wires are swapped. The device still works but the switch on a lamp, for example, disconnects the neutral instead of the hot — meaning the socket stays energized even when "off." Simple fix (rewire the outlet), but a real hazard.

Open ground: The outlet shows as grounded (three-prong) but there's no ground wire connected. Common in older homes where someone replaced two-prong outlets with three-prong without running a ground. Options: run a ground wire, install GFCI protection, or replace with two-prong outlets.

Bootleg ground: Someone connected the ground terminal to the neutral terminal at the outlet. The tester reads "correct" but there's no actual ground path. This is more dangerous than an open ground because it creates a false sense of protection. You need a more advanced tester or visual inspection to catch this.

Dead outlets: Note them. They indicate a tripped breaker, broken connection, or abandoned circuit.

GFCI (Ground Fault Circuit Interrupter) Protection

GFCI outlets detect current leakage (as little as 4-5 milliamps) and trip in 1/40th of a second. They prevent electrocution in wet locations.

Where GFCI is required (current code — older homes may not have it):

• Bathrooms
• Kitchen countertops (within 6 feet of the sink)
• Garage
• Exterior
• Unfinished basement
• Crawlspace
• Laundry (within 6 feet of the sink)
• Pool and spa areas
• Boathouses

Testing protocol:

1. Press the TEST button — the GFCI should trip (indicator changes, power cuts)
2. Plug in your tester, press the GFCI test button on your tester
3. Press RESET to restore power
4. If the GFCI doesn't trip on test → replace it. A GFCI that doesn't trip is providing zero protection.

Note: A single GFCI outlet can protect all downstream outlets on the same circuit. So you may test a standard outlet in the garage and find it's GFCI-protected by a GFCI outlet near the panel. This is acceptable.

AFCI (Arc Fault Circuit Interrupter) Protection

AFCI breakers detect dangerous arcing conditions (damaged wires, loose connections) and trip before a fire starts.

Where AFCI is required (current code):

• All 15-amp and 20-amp branch circuits in living areas (bedrooms, living rooms, dining rooms, hallways, closets, etc.)

AFCI requirements have expanded with each code cycle since 2002. Many existing homes have AFCI only in bedrooms (2002-2008 code) or not at all (pre-2002). Note the absence but understand it's not a defect in an older home — it's the code under which it was built.

Grounding and Bonding

Service Grounding

The electrical system must be grounded. Check for:

• Ground rod(s): Typically one or two copper-clad rods driven into the earth, connected to the panel's grounding bus.
• Water pipe bond: A ground clamp on the main water supply pipe within 5 feet of where it enters the building. If the water supply is plastic (PEX or CPVC), this doesn't exist — and the system relies entirely on ground rods.
• Supplemental grounding: Some homes ground to a concrete-encased electrode (Ufer ground) or a ground plate.

Bonding

Bonding ensures all metal components are at the same electrical potential. Check:

• Gas piping is bonded
• Water piping is bonded
• Metal HVAC ducts are bonded (when accessible to check)
• The neutral and ground are bonded at the main panel (and ONLY at the main panel — they should be separate at sub-panels)

Neutral-ground bond at a sub-panel is a common defect in homes with detached garages or additions. It can create parallel paths for current and energize metal components unexpectedly.

Exterior and Outdoor Wiring

• All exterior outlets must be GFCI-protected and have weatherproof covers (in-use covers if anything is plugged in)
• Exterior wiring must be in conduit or rated for outdoor exposure (UF cable for burial, appropriate cable types for surface mounting)
• Service mast and weather head condition — the inspector can note visible damage or cable wear at the service entrance, though the utility's cable from the pole to the weather head is outside inspection scope
• Landscape lighting, pool equipment, hot tub wiring — note what's visible, recommend evaluation for anything that looks unprofessional

Smoke and Carbon Monoxide Detectors

This isn't technically "electrical inspection" but it's part of the electrical section in most reports:

• Smoke detectors: Required in every bedroom, outside each sleeping area, and on every level (including basement). Should be interconnected in newer construction (one goes off, they all go off).
• CO detectors: Required on every level with a fuel-burning appliance, fireplace, or attached garage.
• Age: Smoke detectors should be replaced every 10 years. CO detectors every 5-7 years. Check manufacture dates.
• Power source: Hard-wired with battery backup is current standard. Battery-only is acceptable in older homes but note it.

Common Electrical Defects by Era

Pre-1950: Knob-and-Tube Era

• K&T wiring (often modified or spliced into modern wiring incorrectly)
• No grounded outlets
• 30-60 amp service (grossly undersized for modern use)
• Fuse boxes instead of breaker panels
• Two-prong outlets throughout

1950-1970: Post-War Boom

• Federal Pacific or Zinsco panels
• Aluminum branch wiring (1965-1975)
• Ungrounded outlets in many locations
• 100-amp service
• Limited outlets per room (modern loads exceed original design)

1970-2000: Modern Wiring, Older Standards

• Copper Romex wiring (good)
• No AFCI protection
• GFCI only in some locations (code evolved through this period)
• 100-150 amp service
• Adequate for the era, may need upgrades for modern loads

2000-Present: Current Standards

• AFCI and GFCI protection throughout
• 200-amp service standard
• Tamper-resistant outlets required in all residential locations
• Arc-fault protection in nearly all living spaces
• Interconnected smoke/CO detectors

Red Flags: When to Recommend an Electrician

Some findings are note-and-move-on. Others warrant a professional evaluation:

Recommend immediate evaluation:

• FPE or Zinsco panels
• Evidence of overheating anywhere (melted insulation, scorched outlets, warm cover plates)
• DIY wiring that bypasses the panel (direct connections to the meter)
• Exposed live conductors
• Missing or non-functional GFCI in wet locations
• Gas smell near electrical components

Recommend evaluation at buyer's convenience:

• Aluminum branch wiring (if no signs of overheating)
• Sub-panel with neutral-ground bond
• Knob-and-tube that appears unmodified
• Undersized service for current loads
• Multiple double-tapped breakers

Note but don't panic:

• Absence of AFCI in homes built before code required it
• Two-prong outlets in older homes (legal as-is, but limits what you can plug in)
• Painted-over outlets or switches (cosmetic, but indicates lazy renovation)
• Missing knockout blanks on panel cover

Documenting Electrical Findings

The biggest challenge with electrical inspection isn't finding the problems — it's describing them clearly enough that a homebuyer understands why they matter and what to do about them.

"Double-tapped breaker at panel" is accurate. But does the buyer know what that means? Does their agent?

Better: "Two circuits share a single breaker terminal in the main panel. This connection type can work loose over time, creating a potential fire hazard. A licensed electrician can install an additional breaker or use a breaker rated for two conductors. Estimated cost: $150-$300."

That's the difference between a report that informs and a report that just documents. The best inspection professionals narrate their findings in plain language while maintaining technical accuracy — and modern voice-to-report tools make that natural-language approach the default rather than the exception.

ReportWalk turns your spoken observations into structured, professional inspection reports. Describe what you see at the panel, and AI handles the formatting, organization, and technical language. Available for iOS.