Remember: just because a DIY plumbing project looks easy on your favorite home improvement show doesn't mean you can tackle it yourself without experience. Also, don't make the mistake of assuming you know how to fix the problem just because you've diagnosed the issue.
Problem 1: Voiding Home Warranties
Did you know attempting your own repairs can cause you to void your home warranties on appliances like the dishwasher or garbage disposal? Home warranty companies are notorious for this and, while many receive complaints from consumers, most problems with these companies stem from homeowners who simply don't know the limitations of their agreement. Attempting to fix the problem yourself without the help of a professional plumber is the most common disqualifier for home warranties.
Problem 2: Creating a New Problem
If you don't know what you're doing, including how the complete plumbing system in your home works and how it's put together, you may inadvertently fix one problem only to cause another that doesn't become apparent for some time. At this point, calling a professional is necessary but it'll end up costing more than if you'd just had the pro take care of the first job.
Problem 3: Issues Selling Your Home
Finally, attempting your own DIY plumbing projects can end in disaster when you try to sell your house. If your plumbing repairs aren't up to code or they don't pass inspection, you can either lose out on a potential buyer or end up putting more money into the problem to get your home sold.
There are DIY projects that are rewarding and save you money and then there are plumbing projects. If you've attempted your own plumbing project and you find you're in over your head, get reliable plumbing services from a professional in town. Major problems are especially likely if you have old plumbing or it was poorly installed the first time.
Image: Daniel Morrison at Flickr