I have only basic elect. knowledge and really struggled trying to find an open neutral on a kitchen circuit. All receptacles were wired correctly but the problem persisted. Haas was called in and the tech was able to trace the problem to a faulty receptacle in the dining room. It had melted and was affecting the kitchen due to questionable wire run. Everything was fixed, wires reset and all debris cleaned up. Great experience. I have used Haas previously and will again when needed.