We had three plumbers check our toilet effluent line, which connected with the shower, as it would backup at times. The first ran a rooter, which he said located a break in the line outside the house in the yard where it didn't make sense -- but he was right. We had another come to scope the line but he didn't bring a scope and thought it just needed to be rooted with a more industrial device. After that failed, we tried to get it scoped but again the person did not show up. Then I contacted Trenchless, which located the break by scope at around the same place the first guy located it. However, it turned out the previous home owners had the line plumbed into a dead line that was capped and not on the city inspector's records. Trenchless then replumbed it to the right line and we've been good so far.