Plumbing issues that seem small can quickly escalate into major problems that cause serious damage to a home and require very costly repairs. You shouldn't immediately call a plumber whenever a concern related to sinks or toilets comes up, but you need to be aware that a seemingly small dilemma can indicate a much more involved plumbing problem.
With a balance between self sufficiency and knowing when to call a professional in mind, let's look at times when you can go the do-it-yourself route for a plumbing fix, and when to call a professional:
Call a plumber: Foreign objects flushed down the toilet
Clearing a simple blockage is a dirty job but one that many people can do themselves. That's not the case for foreign objects that get flushed, however. Whether it's a kid flushing a toy on purpose or an accidental drop of a toiletry, you'll need a plumber to use both experience and specialized tools to clear the problem before it becomes more serious. An untreated blockage by a foreign object can cause further damage if it gets caught in the toilet's trap or in the sewage line, as Popular Mechanics pointed out. This isn't an easily resolved concern, so call a plumber soon after if this happens.
DIY: Change your shower head
Your current shower head may break, or you may simply want to upgrade and get a more powerful stream of hot water to wake you up in the morning. No matter the specifics, changing a shower head is generally a job that you can do yourself. Besides the head itself, the only other specialized tool you may need is thread seal tape to create a tight fit for the head - although it's not always necessary. The lack of constant water flow to the area and easy access to it makes changing your shower head a good DIY project.
Call a plumber: Broken or malfunctioning water heater
Water heaters are complicated machines that tap into an external power source, such as natural gas or oil, to provide hot water for a shower or washing dishes. The complexity of these devices and the potential for danger related to their fuel sources means they're better left to the professionals. There's too much of a chance for both damage to the heater and bodily harm to you. This is one area where getting a certified professional on the job is well worth the cost.
DIY: Fix a jiggling toilet handle
The most likely culprit behind a jiggling toilet handle is a loose or otherwise faulty flap valve, as Reader's Digest pointed out. The toilet tank is easily accessible on the vast majority of models, and toilets have separate water shutoff valves, usually by the base where the pipe connects to the unit. As you can turn the water off and access the flap valve - the relatively soft piece of rubber or plastic inside the tank - this is another easy fix, and a cheap one as well. You can do the job yourself for under $10, there's little chance of breaking anything valuable if you're careful and there are plenty of instructional guides on YouTube if you need a visual aid.
Call a plumber: Renovations and remodeling
Making large-scale changes or simply want to replace a major fixture? Don't do it yourself. Licensed plumbers will perform high-quality work and leave you with a secure setup around which you can paint, decorate and otherwise change the appearance of your home. A leaky connection or poor coupling can lead to water damage and negatively impact those new renovations.
DIY: A simple clog
As veteran Las Vegas-area plumbers Butter Plumbing pointed out, a simple clog is a relatively easy fix for a homeowner or renter. With a sink, bathtub or other drain, you can use the appropriate type of plunger to attempt to clear a blockage, especially if the lack of drainage or slow progress is recent. You shouldn't keep trying to clear a blockage if a plunger doesn't work, however.
Call a plumber: A complicated clog
If a blockage doesn't clear with plunging and the pipes remain backed up, it's a good idea to call in a professional. Using other tools in an attempt to clear a clog, whether it's a straightened coat hanger or a liquid pipe cleaner sold at a hardware store, can damage pipes and lead to costly repairs. In most cases, bringing in a plumber will save money - at least in the long term - in such a situation.
DIY: Adjust water pressure
Adjusting the pressure in sinks, showers and hoses may sound complicated, but it's often a task the average homeowner or renter can complete on his or her own. As National Builder Supply pointed out, changing water pressure can be as simple as adjusting the valves under the sink housing. For both showers and sinks, another strategy is to thoroughly clean the heads and aerators. Hard water and similar problems can leave deposits on faucets and shower heads over time, blocking water flow. If none of these approaches work, then it's likely time to bring in a plumber.
Call a plumber: Leaks in the ceilings, walls or floors
A leak isn't always cause to get in touch with a professional, but many times it is. Any sort of leak where the source isn't immediately visible, such as pipes running behind walls or between the floors of a home or apartment, is cause to immediately get in touch with a plumber. These leaks can cause mold, structural damage and other serious consequences. Contacting a professional is simply a good decision in this situation.
In short, there's a good number of things you can fix yourself, but leave the big jobs to the plumbers who are certified and qualified to do them. In the long run, when your new water heater doesn't break and your sewage line doesn't back up and overflow, you'll be happy you did.