Hey all, long time lurker, first time poster here! I have a couple of questions regarding a rewire job my wife and I had done on our new (old) home. The house was built just after WWII and a home inspection found that it had a mish-mash of wiring. Some new Romex for places like the kitchen (good!), some aluminum (uh-oh), and some much older copper with no ground. The panel was a 100 amp service IIRC and was maxed out. We paid to have a "complete" rewire done. I specifically stated a few major things we had to have corrected to the electrician doing the job. 1. Upgrade to a new 200 amp service. 2. All aluminum MUST GO. 3. Ground all of the outlets 4. Various other minor things like new circuits and outlets and such. The service panel was upgraded to 200A, and to my knowledge all the aluminum is gone. None enters the main panel and every outlet, switch or junction I've worked on or checked is copper. Now that I've explained that, I can finally ask my questions: One thing that concerns me is my home's grounding. The electrician installed a new grounding rod and grounded the new box to it. However, the old system was grounded to the cold water pipes as many old homes were, and for some reason or other he left this ground wire in place. This concerns me for obvious reasons, but I'm not touching it without talking to an expert. To make matters even more hairy, I'm not certain that this is even a valid ground anymore since a previous owner interrupted the pipes in different locations with PVC fittings. I've visually traced the pipe from where the grounding wire is attached to them (near the breaker panel) to where the pipes actually enter my home from the street, and it's not a continuous metal path the whole way - PVC fittings interrupt it. Should I leave this connected? It is probably still acting as a ground through some convoluted path in my plumbing, but can the difference in potential between the pipes and the new rod cause issues? The second thing I'm curious about is all of the outlets that were supposed to be grounded. I used one of those simple plug-in outlet testers which lights up to tell you of any problems and it reads that all the outlets are grounded and wired properly. However, I opened one recently to replace a damaged outlet and found NO ground wire and old two wire copper still coming into the junction box. All of the other outlets that already existed (not the new ones he installed) are the same. No ground wire, nothing connected to the grounding screw, but the outlet still reads grounded on the little tester. Is it possible he grounded the metal work boxes themselves? If he did so, should the outlets themselves be pigtailed to the box, or are the mounting screws sufficient? I actually don't think he did this since I've checked carefully and see no evidence they fished anything new to any of these outlets. I have a sneaky suspicion this guy "cheated" somehow to make the old outlets appear grounded to a simple tester. I need to test these mystery outlets with my multimeter. Correct me if this is wrong: If they are properly grounded I should read 120V from hot to neutral, 120v from hot to ground, and 0V from neutral to ground, correct? If not, what's the proper way to test? Thanks for any advice guys. Sorry my post is so long winded, but I wanted to make sure I gave enough info for you to help.