Every year in my apartment building in the City, they shut off the building water and clean the water tank on the roof. They get it completely free of dirt and sediment and everything else and flush it thoroughly before they refill it with water and reopen the connection to the building. For whatever reason, the shutting off of the water and turning the water back on stirs up sediment, and the water in the building turns a really gross Brown for about 6 hours, after which it gets lighter, and after which it goes back to its usual perfect clarity. Similarly, a year or so ago, I noticed the water in the house in the country was suddenly flowing a dark rust color. Every faucet in the house. Couldn't understand what the problem was. When I looked outside on the street I saw a giant Yellow hose, about the diameter of a basketball, running up the center of the street. I walked out and looked at it, and realized it was a fire hose, running from the fire hydrant at the corner up the hill around the corner and out of sight. Turns out there was a huge fire at our neighbors house at the top of the hill, and the fire trucks were pumping as much water as they could from wherever they could get it. This stirred up sediment in the lines, of course, and not surprisingly, 12 hours later, back to normal. I recently watched a consumer video about how the friendly guys at the quick Lube were selling unnecessary fluids to people. In the hidden camera, the super friendly, professional, kind, concerned technician tells the Undercover reporter that she needs a complete brake flush and transmission fluid. He patiently explains that transmission fluid is supposed to be pink, but that hers was brown, and smelled like burnt toast. He explained that this indicates that the fluid was bad. He also explained something about the color of the brake fluid, and said it indicates that it is old and unsafe. They then showed a video of him saying the exact same thing to three other Undercover operatives. Exactly the same speech to every person that came through the door. What he didn't know, and couldn't know, was that immediately before bringing the cars to the Lube Center, a mechanic of unquestionable skill had replaced all of the fluids in the cars. They needed nothing. And all the cars had been adjusted to be in perfect running condition. When confronted, the employee explained that the speech about colors and smells was the way he was trained by the owner, and that he was told to be friendly and knowledgeable and patient when explaining the issues, but that he should say basically the same thing to everyone. I think you can take these three stories together, and deduce what this so-called plumber was up to. HJ, our revered contributor, hit the nail on the head. This guy was concerned about himself, not about you, and the problem will most likely rectify itself, by itself, within a few days. You did the right thing to hold the guy off. You most likely don't need to consult anybody else.