Most people picture a burst pipe in the wall when they think about plumbing failures. In real homes, the parts that fail first are smaller and a lot easier to reach. Faucets, the little shutoff valves under your sinks and toilets, and the flexible hoses that connect them all wear out on their own schedule. The good news is they almost always warn you first, if you know what to look for.
This is a guide to reading those warning signs. We don’t offer plumbing services and we’re not a contractor, so think of this as a neighbor walking you through what’s normal, what’s not, and when it’s time to bring in a licensed pro.
These parts are designed to wear out
It helps to start with the right mindset. A faucet isn’t a permanent part of your house the way a stud or a joist is. It has moving pieces, rubber seals, and springs inside, and those break down with use and time. The same goes for valves and supply lines. They’re consumable parts. Treating them as “install it and forget it” is how a slow drip becomes a ruined cabinet.
In much of the Bay Area, water hardness pushes that wear along faster. Homes served by Zone 7 and various city systems in the Tri-Valley, along with parts of the EBMUD and Cal Water service areas, see a fair amount of mineral content in the water. That dissolved calcium and magnesium leaves scale behind. You see it as the white crust on a showerhead or aerator, but the same buildup is happening inside cartridges and on the tiny sealing surfaces of a valve. Scale keeps seals from seating cleanly, and that’s a common reason a faucet starts dripping years before you’d expect.
Faucets: what worn-out looks like
A faucet talks to you when it’s failing. The most familiar sign is a drip that won’t quit no matter how hard you crank the handle. On older faucets with rubber washers, that means the washer or the valve seat it presses against has worn down. On newer cartridge faucets, the cartridge itself is worn or scaled up. Either way, tightening harder won’t fix it and can crack something.
Other tells worth noticing:
- The handle gets stiff, gritty, or wobbly, which often means scale buildup or a worn cartridge.
- Water pressure at that one faucet drops off, usually a clogged aerator from sediment or scale, sometimes the cartridge.
- You spot water pooling around the base of the faucet or inside the cabinet below, which can mean a worn seal where the faucet body meets the sink.
- The spout sputters or spits air.
A clogged aerator is often a quick clean. A persistent drip or a leak at the base usually means an internal part has reached the end of its life and needs replacing.
Supply lines: the quiet risk
The flexible hoses running from the valve up to your faucet or toilet are easy to ignore because they sit out of sight. They’re also a frequent source of real water damage, because when one lets go it doesn’t drip, it sprays.
Not all supply lines age the same. The older thin plastic lines and the chrome-coated ones can get brittle or corrode over time. Braided stainless steel lines, the kind with the woven metal sleeve, hold up much better and are what you’ll see on most newer installs. Even those aren’t forever.
When you’ve got the cabinet open, look for a few things. Rust or green corrosion at the metal crimped ends. Any bulge or blister in the braided sleeve, which is a sign the inner tube is failing. Stiffness or a kink where the line should flex. Dampness or mineral crust at either connection. Any of those means the line is living on borrowed time. Plenty of homeowners just swap the supply lines whenever they replace the fixture they feed, since the part costs very little next to what a leak can do to a floor.
Shutoff valves: the part you forget until you need it
Under every sink and behind every toilet there should be a small valve called an angle stop. Its whole job is to let you cut water to that one fixture without shutting off the whole house. The catch is that a valve nobody touches for fifteen years can seize up or fail right when you finally reach for it.
The older multi-turn angle stops, with the round handle you spin several times, are the ones most likely to give trouble. They can freeze in place, or start weeping from the stem the moment you operate them. Quarter-turn valves, which move with a simple lever, tend to be more reliable.
It’s worth gently testing these once in a while. Turn one off, check that the water actually stops at the faucet, then turn it back on and watch for any new dripping. If it won’t move, or it leaks after you’ve worked it, that valve is worn out. Don’t force a stuck one, since that’s how an old valve snaps off and turns a quiet afternoon into a scramble for the main shutoff.
Speaking of which, know where your main shutoff is, and know how to use your water meter shutoff and your gas shutoff too. In earthquake country that last one matters. Many East Bay homeowners also run into the EBMUD Private Sewer Lateral program, which can require testing or repairing your sewer lateral when you sell. That’s a different system from the supply side covered here, but it’s a good reminder that the plumbing you don’t see still has a lifespan.
A simple yearly habit
Once a year, open the cabinets under your sinks and look behind the toilets with a flashlight. You’re checking for moisture, corrosion at fittings, bulges in supply lines, and stiff or weeping valves. Run your hand along the connections. Wipe everything dry and check again in a few days so a fresh damp spot stands out. Five minutes per fixture catches most problems while they’re still cheap to deal with.
When to call a licensed plumber
Some of this is genuine homeowner territory. Cleaning an aerator or even swapping a supply line is within reach for a lot of people. Other situations call for a pro, and there’s no shame in that line being early.
Bring in a licensed plumber when a shutoff valve is stuck or leaking, when a faucet leaks from the base or won’t stop dripping after you’ve tried the basics, when supply lines feed an older galvanized or early copper system that you’re not sure how to handle, or any time you’re not fully confident you can shut the water off and put it back together dry. If water is actively coming in and you can’t stop it, shut off the main and call right away.
Before you hire anyone, confirm they hold an active California contractor’s license. You can look up any plumber by name or license number for free at the CSLB website, cslb.ca.gov, and check that the license is current and in good standing. It’s a two-minute step that protects you, and any reputable plumber expects you to do it.