Section 3 · Plumbing
Plumbing Repair Guides
Home plumbing has two sides: supply pipes that bring clean water in and drain lines that carry used water out to the sewer. Most repairs start with knowing which side has the problem. Use the table on this page for a first check, then follow the guide for your fixture.
Choose your appliance
- Faucets
Every faucet has a valve that opens and closes the water: a cartridge, a ball with seats and springs, or a washer on a stem. Most drips start with a worn part in that valve or with grit in the aerator. Find your faucet type, then use the problem table for the first check.
- Drains
Every sink, tub and shower drains through a U-shaped trap into a branch line, and the branches join the main line to the sewer. One slow drain is a local clog you can usually clear. Several drains backing up at once points to the main line. Start with the table, then keep grease and wipes out.
- Toilets
A toilet has two jobs: the tank stores water and releases it in one rush, and the bowl's trap carries waste to the drain. Most problems are in the tank, where a flapper and a fill valve do almost all the work. Start with the problem table, then use the upkeep notes to catch leaks early.
- Garbage Disposal
A garbage disposal is a motor under the sink that spins a plate. Two swiveling impellers push food against a toothed ring until it is fine enough to wash down the drain. Jams, a tripped overload button and lost power explain most problems; leaks come from the joints around it.
How water moves through your home
Every home has two plumbing systems that meet at the fixtures. Supply pipes bring clean water in to faucets, toilets and appliances. Drain lines carry used water away to the sewer lateral, the pipe that runs from the building to the public sewer main in the street.[1] In Los Angeles County, the property owner owns that whole lateral and must keep it flowing and free of roots and grease.[1] Rules differ by city, so check yours.
Small supply leaks add up. The EPA says the average household's leaks can waste more than 9,300 gallons of water a year. Nine percent of homes have leaks that waste 50 gallons or more a day.[2] A faucet that drips once per second wastes more than 3,000 gallons a year.[2] Fixing easy leaks can save about 10 percent on a water bill.[2]
That split between supply and drain sorts most problems. A drip or a running toilet wastes clean supply water around the clock until someone fixes it. A slow sink, a gurgling tub or a backup is a drain problem. The table below starts from what you see, so you can tell which side to work on.
Plumbing safety basics
Shut off the water to a fixture before you take it apart. Find your home's main water shutoff before you need it, and make sure everyone in the house knows where it is.
Stop and call a licensed plumber when a leak is inside a wall or ceiling. Do the same when water comes up through a floor drain or when a shutoff valve will not close.
Common plumbing problems and the first check
Each first check below takes a few minutes and no special tools. It tells you which guide to open next.
| Symptom | First check | Guide |
|---|---|---|
| Slow or stopped sink or tub | Run water in another fixture nearby and note whether it drains slowly too before you plunge anything. | clear a clogged drain |
| Faucet drips | Close the handle firmly and count the drips, since one drip per second wastes more than 3,000 gallons a year.[2] | fix a dripping faucet |
| Outdoor spigot leaks | Check the garden hose for leaks at its connection to the spigot before you work on the faucet itself.[2] | outdoor faucet leak fixes |
| Water on the floor at the toilet | Dry the floor, flush once and watch where new water shows up: the base, the tank bolts or the supply line. | water around the toilet base |
| Toilet runs or refills on its own | Put a few drops of food coloring in the tank and wait 10 minutes without flushing; color in the bowl means a leak.[2] | toilet tank repair steps |
| Disposal hums or will not run | With the switch off, gently press the red reset button on the disposal; if it will not stay up, wait ten minutes and try again.[3] | get a garbage disposal running again |
| InSinkErator jammed | With the power off, work the self-service wrench or a 1/4-inch Allen wrench back and forth in the hole at the bottom center.[3] | InSinkErator disposal fixes |
Browse by fixture for more detail: faucet repair guides, drain repair guides, toilet repair guides and garbage disposal guides.
Plumbing maintenance that prevents leaks and clogs
Keep grease out of the drains. Los Angeles County Public Works says fats, oils and grease harden and stick to the inside of sewer pipes, and can block them over time.[1] Wipe greasy pans with a paper towel and put the towel in the trash.
Check toilets once a year with the food coloring test. The EPA says a worn flapper can make a toilet flush on its own or leak thousands of gallons a year without a sound. It suggests replacing the flapper at least every five years.[2]
Watch your water use. The EPA says a family of four that uses more than 12,000 gallons a month could have a serious leak.[2] It suggests looking at use in a colder month, such as January or February. To test for a hidden leak, read the water meter before and after a two-hour period when no one uses water.[2] If the reading moves, water is escaping somewhere.
Check outdoor water each spring. The EPA advises checking an in-ground irrigation system each spring before use, and checking the hose connection at the spigot.[2]
Know what wears out. A 2007 NAHB study gives kitchen faucets about 15 years and bath faucets 20 or more. Toilets can last a lifetime, but the parts inside the tank need upkeep. Food waste disposers last about 12 years.[4]
Sources
“Fix a Leak Week” · accessed
“Study of Life Expectancy of Home Components” · PDF · Table 1, section 1 Appliances (Disposers) and section 9 Faucets & Fixtures · accessed
How this page was made
This page was drafted with AI assistance from the manufacturer and safety sources listed above, then checked against those sources in an AI-assisted review. No licensed technician reviewed it. Last reviewed . Our methodology