My receptacles aren't working in my living room. Why?
My receptacles aren't working in my living room. Why? I get that call about a dozen times a year, and I always follow it with a question. Have you been using a space heater, or, do you have a window air conditioner plugged into the wall? Why would those questions be relevant? Because both of those pieces of equipment generate heat in order to fulfill their purpose.
Heat can cause wiring to breakdown. If a wire is not properly sized for the load it's under, there can be problems. Let me give you an example. A 1500 watt heater makes you feel warm and toasty on those cold Winter days, but there is a cost beyond the electric bill. Let's say you have a space heater plugged into a living room outlet, and that circuit is a 15 amp circuit. That would be common in a living room.
A 1500 watt heater can require 12.5 amps to keep it operating at optimal level. Now, the safe operating amperage of a 15 amp residential circuit is 12 amps. That 12 amp load is 1440 watts. Can you see a conflict here? Let's assume the circuit is like most circuits in an average living room and let's add a few lights, a TV, DVD player, maybe a modem and an air cleaner. Just with the heater, you are above the safe max the circuit should carry. When you start adding other items, the circuit soon becomes overloaded. It would be unusual for a living room to be the only thing on a circuit, so there may be a bedroom, a hallway or another room with all of the above items and maybe another portable heater.
Let's add another issue to this scenario. What if the receptacles are back-stabbed? What does that mean? Backstabbing is a wiring technique where the wires are inserted into holes in the back of the device. The receptacles are designed to take this style wiring (on 15 amp circuits) and it is completely UL approved. The problem comes back to heat.
When a portable heater or air conditioner (which generates heat in order to create cold) is plugged into one of these back-stabbed devices, the device heats up and cools down and heats up and cools down. Eventually, the wires no longer make a firm contact, and over time, they begin to have trouble providing power to the device. That environment generates heat on the wires which causes them to become brittle and it causes the insulation to melt away, and it can cause the device (receptacle or switch) to deteriorate. At some point, it will cause the device to breakdown and stop operating.
Backstabbing is one the most dangerous wiring techniques in any home. Inserting a portable heater or air conditioner into a receptacle that is on a 15 amp circuit is another. Combine those two, and at some point, you will have issues. The receptacles can breakdown and stop passing electricity on to devices down-line.
Let me give you a rule of thumb. Never plug a space heater into any circuit that is below 20 amps. Check your receptacles to see if they are back-stabbed. If they are, have a qualified electrician take them out and put the wires directly on the screws provided with the receptacle. Both of those rules can save an electrical breakdown, a power outage in part of your home, and ultimately, it can save your life.