I've been in the plumbing trade for nearly 20 years, and I can tell you that without a doubt that my most difficult customers are ones who've attempted their own plumbing repairs, and simply lack the skills to properly complete the job.
So why is this more problematic than a regular plumbing job?
Well, there's a number of possible problems that emerge from these jobs!
A battle of the plumbers
Aborted plumbing jobs by the household owner often feels like a defeat to them. Sometimes they're very defensive of their work, so I have to be careful with my words when I diagonose the problem. I never aportion blame (just antagonises) and keep everything neutral. Having said that, still some customers see me as some kind of criticism of the DIY they carried out. Kid gloves are required!
Hiding the real problems
Associated with the above point is that the customer will sometimes not reveal the extent of the problem. And so, I have to see the damage firsthand and make an independent assessment based on my own eyes and not rely on their account of the problem.
The customer ends up paying more and is not happy about that
It's brave - if not often foolhardy - to simply "have a go" at plumbing without any training. However, when things go wrong, it often means you're paying way more than simply hiring a plumber in the first instance. I'm often having to undo their work (which takes more time than simply addressing the original problem) and of course, the customer may have already spent money on unnnecessary tools and materials. Again, it's a tricky situation when quoting for such jobs.
The classic "a little knowledge is dangerous" problem
This is when an unskilled person believes their opinion is as equally valid as a skilled, experienced person's opinion. And so, I sometimes find that the customer is questioning my diagnosis, and then my execution of the job. There are instances where the teacher learns from the student, but in 20 years, I've never found that with specific plumbing jobs! Experience counts for a lot, but it's hard to convince some people!
To sum it up, keep it simple - call a qualified, experienced plumber if you have plumbing issues! Article kindly provided by local-plumbers.org