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Electrical Checklist For New Owners of Old Houses

knob and tube wiring in an old home - wilcox-electric-dcOld homes, such as many in DC's historic neighborhoods, have their charms to be sure. We love them! But the purpose of any home is to provide a safe and comfortable shelter and living space for your family. Outdated electrical wiring is a particular concern to new owners of old houses.

We've put together a checklist of three critical electrical issues, in case they are present in your new old home.

Knob and Tube Wiring

Knob and tube wiring, also called K&T wiring for short, can be found in most pre-1940s homes that have had no electrical upgrade. K&T wiring features two separate wires that run independently and connect where needed for lights, outlets, and switches. It is not grounded, is air-cooled (meaning no protective insulation), and is typically joined in unprotected and unsafe junctions, which may even be exposed without so much as a wire nut for protection.

This type of household wiring is wholly inadequate for the modern demands of households today. Newer appliances loaded with features and numerous electronic gadgets and devices that we depend on all draw significantly more power through the system than families used before the 1940s. Ungrounded and exposed wiring and electrical connections present safety risks and should be considered a priority.

Old Electric Panels and Breaker Panels

Similar to old methods of wiring, older homes typically feature outdated and inadequate electric panels that cannot carry ample current to power your needs safely, if at all. Also, if circuit breaker panels are present, they are likely dated and virtually useless. Old breakers were designed to overheat and burn out if overloaded, creating a risk for fire.

But old, dated breakers may not even work, allowing overloaded circuits and wiring to bear far too heavy electrical loads until they burn out, meltdown. It can get dangerous. These older homes were typically wired for no more than 60 amps, while 200 Amp/240 Volt service is the current standard. Most insurance companies will not insure a single-family dwelling that isn’t wired for at least 100 Amp/240 Volt service.

Two-Pronged Outlets

Another substandard part of old home electrical systems is two-pronged outlets linked to the outdated and dangerous K&T ungrounded wiring system discussed above. The third, partially rounded hole seen on modern electrical outlets, is the ground connection, which is a safety feature.

An old home with outdated wiring will have two-pronged outlets throughout. These outlets must be replaced, along with the wiring, with new 3-pronged, grounded outlets. Also, kitchens, bathrooms, any outlets near water, and all outdoor outlets use Ground Fault Circuit Interrupter (GFCI) Breakers & Outlets. These units have built-in circuit breakers for increased safety.

Congratulations on your recent home purchase. We are confident that you will come to love your new old house - especially once you know it is safe and heavied-up to meet the demands of your very 21st-century lifestyle.


Wilcox Electric, LLC, can provide an electrical safety assessment of your old home to help you locate other areas of concern. We can perform the necessary upgrades to bring your old house up to modern, safe standards. Call 202-546-1010 or message us online to arrange a consultation.