Since you are probably paying a pretty penny for the privilege of having a plumber coming over and looking at your pipes, you should realize that there are a lot of ways in which a plumber could potentially end up tricking you. In situations like this it’s important to try and figure out how you can ascertain whether or not your plumber is worth the money that you are paying for him or her, and luckily for you there are a couple of ways in which you would be able to do this all in all.
One way involves seeing if they are trying to get you to get extra work done that you have not asked them about. A plumber that keeps suggesting extra work for you to do is probably not doing a good job and is just trying to get as much money out of you as possible, so if your plumber ends up behaving in this manner then you should try your best to get rid of them and hire someone else as soon as you can.
Another way in which you can figure out whether or not your plumber is the right kind of plumber for you is by asking them about the various types of plumbing systems that are out there. If they are a legitimate plumber then they will have no trouble at all answering this question, but if they are hesitating or you feel like the answers are not coming to them naturally enough, you could always switch them up with someone else that you feel possesses a little more knowledge all in all. The basic gist of it all is that you should try your best to hire someone good.