How Tap Plumbing Works and When to Call a Professional

What tap plumbing covers and why it matters

Tap plumbing refers to the fixtures, pipes, and valves that bring water into your home and let you control the flow—everything from your kitchen sink to your shower to your outdoor hose connection. When something goes wrong with a tap, the problem is usually one of three things: the tap leaks, it won't turn on or off properly, or the water pressure drops. Most tap issues are fixable without replacing the whole fixture, though sometimes a new tap is cheaper than the repair.

South Carolina's hard water and mineral deposits can clog aerators (the screens at the tap's mouth) and corrode internal seals faster than in other regions, so tap problems here often trace back to buildup rather than wear. Knowing what you're dealing with helps you decide whether to tackle it yourself or call a plumber.

Key Takeaways

• Most tap leaks come from worn washers or seals inside the tap body, which a plumber can replace for $75 to $150 in labor.
• Mineral deposits from South Carolina's hard water clog aerators and reduce pressure; cleaning or replacing the aerator is often a five-minute fix.
• Single-handle taps are harder to repair than two-handle taps, and cartridge-style taps cost more to fix than compression taps.
• Shutoff valves under the sink let you stop water flow to that tap alone, so you can repair it without turning off water to the whole house.

Types of taps and how they fail differently

Compression taps have two handles (one for hot, one for cold) and work by tightening a screw to press a washer against a valve seat. When the washer wears out, the tap drips. Replacing a washer costs almost nothing, but you need a wrench and an hour of time. If the valve seat itself is pitted or corroded, you may need to replace it or the whole tap.

Cartridge taps have a single handle that moves up and down or side to side, and they use a cartridge (a plastic or metal cylinder inside) to mix hot and cold water. When a cartridge fails, the tap may leak, lose pressure, or deliver only hot or cold water. Cartridge replacement runs $40 to $100 for the part, plus labor. Ball taps (common in kitchens) have a rounded cap and work similarly to cartridge taps but are less common in older South Carolina homes.

Ceramic disk taps are newer and more durable; they use two ceramic disks to control flow and rarely need repair. If one does fail, the whole tap usually needs replacing because the disk cartridge is not sold separately.

Common tap problems and what causes them

A steady drip from the spout almost always means a worn washer (compression tap) or a failing cartridge (single-handle tap). A drip from under the tap, at the base, signals a leak in the seal where the tap connects to the sink or counter. This is usually fixable by tightening the connection nut under the sink or replacing the rubber gasket.

Low water pressure at one tap often points to a clogged aerator. Unscrew the aerator (the screen at the tap's tip), soak it in white vinegar for an hour to dissolve mineral deposits, and rinse it. If pressure returns, you are done. If not, the problem is inside the tap body or in the supply line, and a plumber will need to investigate.

A tap that won't shut off completely means water is leaking past the valve seat. In a compression tap, this is usually a worn washer. In a cartridge tap, the cartridge needs replacing. A tap that is hard to turn or stuck may have mineral buildup on the handle stem; soaking the stem in vinegar sometimes frees it, but if it stays stuck, the tap may need replacement to avoid damage.

When to repair versus replace

Repair makes sense if the tap is less than 10 years old, the leak is minor (a few drops per minute), and the tap is a standard type (compression or cartridge). A plumber's visit costs $100 to $200 for diagnosis and repair; a new tap costs $50 to $300 depending on style and finish, plus $100 to $200 in labor to install. If repair and replacement are close in price, replacement is often the better choice because a new tap comes with a warranty.

Replace the tap if it is over 15 years old, if it leaks from multiple places, if the handle is cracked or broken, or if you have replaced internal parts twice in the last five years. Older taps are more likely to have corroded valve seats that cannot be repaired, and the cost of repeated fixes adds up quickly.

If you are unsure, ask a plumber for a quote on both repair and replacement. Many will give you a free estimate, and seeing the numbers side by side makes the decision clear.

How to find and use the shutoff valve

Under your sink, you should see two small valves (one for hot water, one for cold) connected to the supply lines. These are shutoff valves, and they let you stop water to that tap alone without affecting the rest of your home. Before you repair a tap or call a plumber, turn both valves clockwise until they stop. If the valve is stiff or won't turn, do not force it; call a plumber instead, because a stuck valve can break and flood your home.

If there is no shutoff valve under your sink, or if it does not work, you will need to use the main shutoff valve for your house. This is usually in the basement, crawlspace, or outside near the meter. Turning it off stops water everywhere, which is inconvenient but necessary if you have a major leak. After you repair the tap, turn the valve back on slowly to avoid air in the lines.

DIY tap repair versus hiring a plumber

Replacing a washer in a compression tap is a beginner-friendly project if you have a wrench and a screwdriver. Unscrew the handle, remove the packing nut, unscrew the stem, and pull out the washer. Take the old washer to a hardware store to match the size, buy a new one for a dollar or two, and reverse the steps. The whole job takes 20 to 30 minutes.

Cleaning an aerator is even simpler: unscrew it by hand, soak it in vinegar, scrub with an old toothbrush, rinse, and screw it back on. No tools needed.

Replacing a cartridge is harder because you need to identify the exact cartridge type and remove it without damaging the tap body. If you are not comfortable with this, a plumber will do it in 30 minutes to an hour. Cartridge replacement is one of the most common tap repairs, so most plumbers have the parts in stock.

Call a plumber if the shutoff valve is stuck, if you cannot identify the tap type, if the leak is under the sink (not at the spout), or if you have already tried a repair and it did not work. A plumber can also advise whether your tap is worth fixing or should be replaced.

Tap plumbing in older South Carolina homes

Homes built before 1980 often have compression taps with brass bodies and chrome handles. These taps are durable and easy to repair, but mineral deposits from South Carolina's hard water can corrode the valve seat over decades. If you have an old tap that leaks and the valve seat is pitted, replacement may be your only option.

Galvanized steel supply lines (common in homes built before 1970) can also restrict water flow to the tap, making pressure seem low even if the tap itself is fine. If you have low pressure at multiple taps, the problem may be in the supply line, not the tap. A plumber can test the pressure and advise whether you need new supply lines or just a tap repair.

If you are renovating a bathroom or kitchen in an older home, this is a good time to replace old taps with new ones. Modern taps are more water-efficient, less prone to leaks, and come in finishes that match contemporary fixtures.

Frequently Asked Questions

How much does it cost to fix a leaky tap?

A plumber's visit typically costs $100 to $200 for diagnosis and repair. The actual repair (replacing a washer, cartridge, or seal) usually runs $50 to $150 in labor, depending on the tap type and how long it takes. If you do simple repairs yourself, like replacing a washer or cleaning an aerator, the cost is just the part, which is usually under $10.

Can I repair a tap myself if I have never done plumbing before?

Yes, for simple jobs like cleaning an aerator or replacing a washer in a compression tap. Both require only basic tools and take less than an hour. For cartridge replacement or repairs under the sink, it is safer to hire a plumber unless you are confident with tools and can identify the exact tap type.

Why does my tap have low water pressure in South Carolina?

Hard water minerals often clog the aerator (the screen at the tap's tip). Unscrew it, soak it in white vinegar for an hour, and rinse. If pressure returns, you are done. If not, the problem may be inside the tap or in the supply line, and a plumber can diagnose it.

Should I replace my tap or repair it?

Repair if the tap is under 10 years old and the leak is minor. Replace if the tap is over 15 years old, if it leaks from multiple places, or if you have repaired it twice in five years. Ask a plumber for a quote on both; the numbers often make the choice clear.

What should I do if the shutoff valve under my sink does not work?

Do not force it; a stuck valve can break and cause flooding. Use the main shutoff valve for your house instead (usually in the basement or outside near the meter). Call a plumber to repair or replace the stuck valve so you have a working shutoff for that tap in the future.