Many common plumbing problems can be fixed by homeowners with basic tools. Dripping faucets usually need new washers, toilet clogs often clear with a plunger, and drain backups respond to a plumber's snake or baking soda and vinegar. Learning these skills prevents water waste, avoids expensive service calls, and builds confidence.
With an adult, unclog a drain using a plunger or snake. Replace a faucet washer by turning off the valve, disassembling the faucet, and installing a new rubber washer. Help identify leaks under sinks.
All clogs need chemical drain cleaners. (Plungers and snakes work for most clogs and are safer.) Dripping faucets don't matter. (A slow drip wastes thousands of gallons per year.)
From your study of plumbing fundamentals, you know that a home has two distinct systems: a pressurized supply system bringing clean water in, and a drain-waste-vent system removing wastewater by gravity. Most DIY repairs involve one of two failure modes — something blocking the drain side, or something wearing out on the supply side. Knowing which system you're dealing with before you touch anything is the first habit worth building.
The most common supply-side problem is a dripping faucet. A faucet controls flow by pressing a rubber washer or ceramic disc against a seat to stop water. When the washer wears out, it can no longer form a complete seal, and water forces past it drop by drop. The fix requires turning off the water supply valve under the sink, disassembling the faucet handle, removing the old washer, and replacing it — a $2 part and 20 minutes of work. The reason it's worth doing promptly: a faucet dripping once per second wastes over 3,000 gallons per year. That's real money on your water bill, plus wear on the faucet seat that will eventually require more expensive repairs.
Clogged drains are the most common drain-side problem. Your first tool is a plunger — it works by creating alternating pressure and suction that dislodges soft blockages (hair, soap, food debris) rather than dissolving them. Cup plungers work on sinks and tubs; flange plungers are shaped for toilets. For tighter clogs that plunging can't reach, a drain snake (also called an auger) is a flexible coiled cable that you feed into the drain and rotate to break up or retrieve the clog. Both tools solve the vast majority of household clogs without chemicals. Chemical drain cleaners are caustic — they damage older pipes, can splash onto skin or eyes, and often fail on serious blockages while leaving a pipe full of corrosive liquid. Reserve them as a last resort, if at all.
Knowing when to stop and call a plumber is part of DIY competence, not a failure. Signs that a problem is beyond DIY scope: multiple drains backing up simultaneously (indicating a main-line blockage, not a single-fixture clog), water damage or standing water in walls or ceilings, the water supply line itself leaking (not just a fixture), or any repair requiring soldering copper or working on gas lines. The shutoff valve under each sink and toilet, and the main shutoff valve where water enters the house, are the most important things to locate before any problem occurs — in an emergency, finding the shutoff in 10 seconds prevents thousands of dollars in water damage.