We recently plugged a space heater into an outlet in our son’s bedroom and only ran it at night. At some point, all of the lights and outlets in the room except one outlet on the opposite wall stopped working. No breakers were tripped. I shut down every breaker and even the main before restoring them one by one, and it resolved nothing.
I located the circuit for the outlet that the heater was plugged into. One plug in tester said I had a reversed hot neutral, the other said open neutral. A multimeter showed no voltage at the outlet, but the touch tester revealed there was power in the wire behind it. I shut off the breaker and replaced the outlet the heater had been attached to (using wire screws and not the stab backs). It was the last thing on the circuit with only one set of wires in the wall. When I turned the breaker back on, three lights in the hall and the light in an adjacent closet stopped working. There are no GFCI’s on the circuit. I methodically opened every outlet and switch in the room (6 outlets and two separate light/switch combos). I pulled the stab back connections, pushed them in firmly, checked and tightened every pigtail wire nut, and didn’t find anything obviously wrong. I flipped the breaker back on and all of the lights started working again. The outlets are now working also, but still show an open neutral.
The only weird thing I saw was one outlet with wires in all 4 stab connections and an additional set tied into the side screws (so three pairs of wire on this one outlet. I’m assuming it’s switched, but it is behind furniture so not used. I did not pull the fixtures because I’m short and weak and they are heavy.
So in summary, everything is working, but I’ve still got an open neutral somewhere. Any ideas? It appear that this one 15 amp breaker controls 5 lights, 5 switches, and 6 outlets. I did not pull wiring for the three lights that went out after I changed the outlet. They all work now too.